tps5352
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Note: See new Post #49 for further thoughts on how to test for the effects of wheel/tire sizes on range.
*****
Talking Points
- Target audience: Readers new to Rivian and/or electric vehicles in general. (But input from experienced Rivian drivers is welcomed.)
- Premise: Rivian SUVs and pickups are great. But can range be improved (by wheel/tire selection)?
- Justification: Why need/want more range? We discuss the (many) factors that increase, and (relatively few) factors that decrease, the rate-of-loss of battery energy (leading to range reduction). Savvy buyers tend to want the most range possible.
- Focus within the article:
- The most range-efficient Rivian models.
- An introductory look at wheels and tires.
- Four inherent objectives.
- Rivian OEM wheels and factory-recommended tire sizes.
- How to choose among many wheel/tire options, while avoiding undesirable issues?
- What pathways are available to change wheels/tires if increased range is an objective?
I'm an armchair proponent of greater electric-car range.² (For some of us, it's all about “range, range, range.”) I have also become something of a closet (As in hopefully “out of” in 2025?) fan-boy for the full-sized Rivian SUV. The result? How to get the maximum (R1S) range. I acknowledge that there are at least two points of view on range--for example, see one here and another here--both worthy of consideration. For more on this, see Appendix A ("Why Want More Range?).
- Source -
Figure 1. For a recreational-vehicle,
there are some locations where
range is not a luxury, it’s a necessity.
Experienced Rivian and BEV drivers—especially those putting in lots of on- and off-road miles--may know all this. So this article is primarily intended for us newbies (to Rivian and/or to electric vehicles). Though my focus is on the big Rivian SUV and pickup, general lessons may apply to other (future) vehicles, as well.
First Step – Choosing the Most Range-Efficient Model
Some considerations:
- number of motors
- battery size
- wheel size
- tire size, tread design, and efficiency
At the moment³ the stock R1S and R1T vehicles with the greatest range (EPA estimated 410 and 420 miles, respectively⁴) are the Adventure (or “Performance”) Dual Max versions. These most-range-efficient models have two (not 3 or 4) motors, and Rivian’s largest (141 kWh) Max battery. So far so good. What can be done using wheels and tires?
Second Step, Wheels and Tires
I think I’ve heard Martin Brundle (1980s-90s Formula 1 driver and, now, preeminent F1 commentator) on more than one occasion refer to tire science as “magic.” And judging by the number of postings, tires are frequently on the minds of many Rivian drivers. Here are two comprehensive online lists of OEM and aftermarket replacement tires that may be satisfactory for Rivian trucks and SUVs:
- Rivian Tire Spreadsheet (I found a link to these spreadsheets through Reddit. Here is a link right within the Rivian Forums site.)
- RivianTrackR Tire Guide
How might this information help us increase range?
The Effects of Changing Wheel and Tire Sizes
What people may loosely call a "wheel" often means both the central (metal) wheel itself and the outer, inflated, rubber tire. A "wheel set" can be both the (four) wheels and the tires together (plus other parts like the TPMS air pressure sensors, aero-wheel-covers, lug-nuts, etc.). Since wheels and tires are obviously circular, they both have (center to edge) radius, (edge to edge) diameter, (distance around the outer edge) circumference, and width measurements. In addition, tires critically also have tread width and sidewall height. The total height of a wheel + tire together is the tire's diameter (= sidewall height + wheel diameter + sidewall height). Since for any circle radius (1/2 the diameter), diameter, and circumference are all strictly interrelated, to know one is to know all three. Tire tread width, and tire sidewall height, and wheel diameter can vary, however, even if tire radius, diameter, and circumference are held constant.
Considering all the different kinds of vehicles over the years, it is in no way an exaggeration to say that there are an incredibly huge number of different sizes of wheels and especially sizes of tires. Even for one particular vehicle there may be tens or hundreds of different wheel/tire products that will fit (possibly requiring modification). Choosing the best tires in particular can be a major chore (for help, see here, here, or here). And there are many legitimate factors that can influence the choice of tires, including:
- price
- appearance
- weight
- sidewall height
- tread width
- tire pressure
- performance
- wear and durability
- tread design and rubber composition
- usefulness on pavement and in mud, sand, and snow
- intended climate and season
- et cetera, et cetera...
The Effect of Wheel and Tire Sizes on Range
Normally, wheels with larger diameters partnered with tires with correspondingly smaller sidewall heights (lower-profile tires) tend to reduce range. (See also, Appendix B.)
Figure 3. Range generally decreases with larger
wheels and lower-profile tires.
But Rivian’s current choice of wheel-sets for the 2025 Dual Max vehicles for example, and their range estimates, seem to defy this supposition.
- 20” wheels with all-terrain tires – 370/370 miles
- 22” wheels with performance tires – 410/420 miles
So this post will (correctly, I think) assume that (a) decreasing the size of wheels (within reason) while maintaining overall tire diameter (by increasing sidewall height) and (b) replacing deeper off-road and all-terrain tire tread designs with more shallow, pavement-friendly (e.g., “all-season,” “performance,” “touring,” “highway,” etc.) tread versions may tend to help increase range.
By the way, readers might have noticed that Rivian does offer the option of a 20-inch so-called "All-Season" wheel set to ostensibly improve range. But to my knowledge this is only for the (least expensive) R1T and R1S Adventure Dual Standard models.
Sticking With Rivian Stock (OEM) Wheels and Approved Tire Sizes
For this preliminary analysis, I think that considering only Rivian OEM wheels, tire sizes, and tire capacities is wise. This helps guarantee proper fit and safety (and by limiting the number of wheel/tire products makes the analysis more manageable). In addition, a focus has been on wheel-tire combinations that do not require that speedometer software be reprogrammed. (For more on that topic, see here and Appendix C.) If you have the time, peruse this long thread: Scorpion AS+ tire swap (from 20" Scorpion AT) - WOW big difference. In it you can see some of the imagined advantages and real disadvantages of straying outside of the lines (as far as tire size). For better or worse my thinking echoes that of this entry.
To repeat myself, this post is intended as a preliminary start for new Rivian drivers/buyers and not as an extensive review of every possible individual wheel and tire combination. Aftermarket wheels are not considered, for example. (Yet I’m sure that there are many excellent choices available which achieve proper fit, appearance, strength, durability, light-weight, and other desirable characteristics.)
Here is a quick look at first (Gen 1) and second (Gen 2) generations of wheel-tire combinations offered by Rivian for R1S and R1T (click to enlarge):
Figure 4. Rivian OEM Gen 1 (10/21 -5/24) wheels and tires.
Figure 5. Rivian OEM Gen 2 (6/24 -->) wheels and tires.
Summary of Analysis Objectives
The following preliminary wheel-tire substitution analysis includes at least four built-in, inherent objectives:
- To consider possible alternative wheel-tire combinations that may increase maximum range, primarily by reducing wheel size, retaining tire diameter, and avoiding off-road, mud & snow, and aggressive all-terrain tire tread designs.
- To bypass if possible the need to reprogram speedometer software (see Appendix C).
- To utilize Rivian Gen 1 & Gen 2 factory wheels and appropriately matched tire sizes.
- To follow safety guidelines and (specifically) consider tires with Load Indices of at least 116.
Note: For safety reasons, any results that follow must be treated as theory and speculation for discussion purposes. Definitive conclusions would require verification by trusted professional tire experts, proper and safe empirical testing, and/or valid real-world results by experienced drivers in order to substantiate. Increased range is not guaranteed.
Table 1. Some Possible Tire Options for Increasing T1T/R1S Range (Part 1)
(Rivian Generation 1 Vehicles)
(Rivian Generation 1 Vehicles)
| Factory Wheels/Tires | Alternative 1 | Alternative 2 | |
|---|---|---|---|
Wheel Diameter: | 20 | 20 | 21 |
Tire Brand & Model: | Pirelli Scorpion AT+ | ⁵ | ⁶ |
Tire Category: | Light Truck, All-Terrain | Touring, All-Season | |
Tire Size: | 275/65R20 | - same - | |
Tread Width: | 10.83 | - same - | |
Sidewall Height: | 7.04 | - same - | |
Tire Diameter: | 34.08 | - same - | |
Tire Circumference: | 107.07 | - same - | |
True Speed (@65 mph): | 65 | 65 | |
Wheel Diameter: | 21 | 21 | 20 |
Tire Brand & Model: | Pirelli Scorpion Verde⁷ | Michelin Defender LTX M/S2⁷ | ⁸ |
Tire Category: | All-Season, Touring | All-Season, Highway | All-Season, Touring |
Tire Size: | 275/55R21 | - same - | 275/60R20 |
Tread Width: | 10.83 | - same - | - same - |
Sidewall Height: | 5.95 | - same - | 6.5 |
Total Tire Diameter: | 32.9 | - same - | 33 |
Tire Circumference: | 103.36 | - same - | 103.67 |
True Speed @65mph: | 65 | 65 | 65.2 |
Wheel Diameter: | 22 | 20 | 21 |
Tire Brand & Model: | Pirelli Scorpion Zero | ⁸ | ⁹ |
Tire Category: | All-Season, Performance | All-Season, Touring | All-Season, Touring |
Tire Size: | 275/50R22 | 275/60R20 | 275/55R21 |
Tread Width: | 10.83 | - same - | - same - |
Sidewall Height: | 5.41 | 6.5 | 5.95 |
Total Tire Height: | 32.82 | 33 | 32.9 |
Tire Circumference: | 103.11 | 103.67 | 103.36 |
True Speed @65mph: | 65 | 65.4 | 65.2 |
Table 2. Some Possible Tire Options for Increasing T1T/R1S Range (Part 2)
(Rivian Generation 2 Vehicles from June 2024 onward)
(Rivian Generation 2 Vehicles from June 2024 onward)
Note: As of March 2025, it appears that Dual Large, Dual Max, and Tri Max vehicles with the AT Package still receive 34" (Pirelli) tires. (Dual Standard vehicles, only, continue to receive 33" Goodyear Wrangler Territory AT tires, if the all-season wheel-set option is selected.)
| | | Factory Wheels/Tires | Alternative 1 | Alternative 2 |
|---|---|---|---|
| |||
Wheel Diameter: | 20 | 20 | 20 |
Tire Brand & Model: | Goodyear Wrangler Territory AT¹⁰ | ⁸ | ¹¹ |
Tire Category: | All-Season | All-Season, Touring | | |
Tire Size: | 275/60R20 | - same - | | |
Tread Width: | 10.83 | - same - | | |
Sidewall Height: | 6.5 | - same - | | |
Total Tire Diameter: | 33 | - same - | | |
Tire Circumference: | 103.67 | - same - | | |
True Speed @65mph: | 65 | 65 | | |
Wheel Diameter: | 20 | 20 | 21 |
Tire Brand & Model: | Pirelli Scorpion AT+ | ⁵ | ⁶ |
Tire Category: | Light Truck, All-Terrain | Touring, All-Season | |
Tire Size: | 275/65R20 | - same - | |
Tread Width: | 10.83 | - same - | |
Sidewall Height: | 7.04 | - same - | |
Total Tire Diameter: | 34.08 | - same - | |
Tire Circumference: | 107.07 | - same - | |
True Speed @65mph: | 65 | 65 | |
Wheel Diameter: | 22 | 20 | 21 |
Tire Brand & Model: | Pirelli Scorpion AT+ or Pirelli Scorpion MS | ⁸ | ⁹ |
Tire Category: | All-Season, Performance | All Season | All Season |
Tire Size: | 275/50R22 | 275/60R20 | 275/55R21 |
Tread Width: | 10.83 | - same - | - same - |
Sidewall Height: | 5.41 | 6.5 | 5.95 |
Total Tire Diameter: | 32.82 | 33 | 32.9 |
Tire Circumference: | 103.11 | 103.67 | 103.36 |
True Speed @65mph: | 65 | 65.4 | 65.2 |
Table 3. Some Substantive Reasons to Change Wheel Size
| Start With: | Change to 20" Wheel: | Change to 21" Wheel: | Change to 22" Wheel: |
|---|---|---|---|
20" Wheel | - na* - | ? | better performance, appearance |
21" Wheel | greater selection of tires | - na - | ? |
22" Wheel | better range, comfort, noise | ? | - na - |
* na = "not applicable"
Table 4. Some Optional Pathways To Possibly-Increased Range
| Starting Tires | New Wheels Required? | Possible New Tires | Re-calibration Needed? |
|---|---|---|---|
1 - 275/60R20 (33" diam.) AT | no | 275/60R20 (33) AS | no |
2 - 275/65R20 (34) AT | no | 275/65R20 (34) AS | no |
3 - 275/55R21 (33) Road | yes | 275/60R20 (33) AS | no |
4 - 275/50R22 (33) | yes | 275/60R20 (33) AS | no |
| Additional Pathways | (added expense) | |
5 - 275/60R20 (33) AT | yes | 275/65R20 (34) AS | yes |
6 - 275/55R21 (33) Road | yes | 275/65R20 (34) AS | yes |
7 - 275/50R22 (33) | yes | 275/65R20 (34) AS | yes |
Comments
Gen 1 and Gen 2 Wheels (Figures 4 and 5)
- The information in the Figures is from the Rivian website (https://rivian.com/) and other online sources.
- In Figures 4 and 5 (and in the tables within each figure), note the use of color to indicate shared measurements.
- Rivian Gen 1 wheel and OEM tire combinations result in either 33-inch (“33s”) or 34-inch (“34s”) diameter (i.e., ~103” or ~107” circumference) tires. If (a) replacing wheels/tires and (b) trying to avoid the inconvenience of reprogramming speedometer software, try to replace tires with others of the same diameter. (Note that wheel diameter can be changed without necessarily changing the overall tire diameter. See Figure 9.)
The Four Analysis Objectives
(Listed just below Figure 5.)
(Listed just below Figure 5.)
- Consider the four objectives as preliminary guidelines. That said, wheel/tire safety is important when you are dealing with a large, heavy, fast, quick, powerful, and expensive vehicle.
Tables 1 and 2
- This analysis does not specifically recommend what wheel and tire combinations a driver (seeking greater range) should use. That is probably not practicable, as there are far too many unknowable factors that could play a part in making such a decision. Instead, it is up to the interested reader to:
- First, establish the starting wheel and tire sizes.
- Second, examine the best options for alternative wheel and tire sizes, for example that would not require speedometer re-calibration.
|
- There are a number of resources available to select new tires:
- Use one of the online tire-guides cited in this article, for example here.
- Using online tire information, build a computer spreadsheet. (This is initially labor intensive, but eventually provides the easiest and most convenient way to manipulate tire information.)
- Use a favorite tire shop website.
- Visit and talk to tire experts in person. (But use appropriate caution. Tire salesmen are there to sell tires. It is ultimately your responsibility to get the best product.)
|
- In some cases the number of tire options within a specific wheel-size and tire-size category is severely limited or entirely absent. This may be due to an owner's desire to avoid speedometer re-calibration or just to a lack of all-season-like tires that satisfy Rivian weight/safety requirements.
- As others have commented on, it appears that the 21-inch Rivian wheel has led to somewhat of an “orphan product” situation (i.e., an item that, for various reasons, is not considered lucrative and hence not receiving proper development and promotion by [in this case] tire manufacturers).
Tables 3 and 4
- Table 3 is fairly self-explanatory. Experienced drivers may have many other reasons for switching wheel and tire sizes.
- Table 4 is intended to alert readers as to what is in store for various wheel/tire changes--e.g., the added expense of wheel and tire purchase, plus the possible cost of speedometer software reprogramming.
- Unless you enjoy losing money and/or like storing wheels and tires for long periods in your garage, always try to buy a new/used vehicle with the wheels and tires you want. That said, sometimes a deal is too good and you just have to buy a car with the wrong wheels/tires.
- If you plan to eventually search for aftermarket tires to try to improve range, you have a few options (see Table 4). You may want to think about if and how you will dispose of the original tires and (if necessary) wheels (e.g., for storage or sale). Also, which initial wheel and tire size makes the most sense for you and your plans? Another consideration, can you avoid speedometer software re-calibration?
- It is my opinion--and it is just an opinion--that (all else being equal) if maximum range is desirable it would be best to start with a 20-inch wheel and 34-inch tire set, as this provides the largest number of alternative all-season-like higher-profile tire products that (with research or experimentation) may be found to provide improved range. Twenty-inch wheels and 33-inch tires may serve, as well; albeit with fewer available replacement tire choices at this time.
- Readers who make it this far will see that despite all the words (above), the story is not yet complete. It's only just begun. See Post #49 for the next step--how to test the theory that maximum range might be achieved with 20-inch wheels and 34-inch highway tires.
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APPENDICES
APPENDICES
A. More About Range
How to Think About Range as a Number?
There are at least three valid ways to think about range numerically:
- As an official estimate of (maximum) range that a car can be driven when fully charged, often based on U.S. EPA determinations. EPA or other official estimates, provided by auto-makers and other online sources, are usually determined under strict laboratory or field conditions, and are often higher than what an average driver can expect to achieve in real-world conditions (see Range Consideration Number 2).
- As a real-world (average) range that drivers can achieve while driving in actual situations. Usually, these values will be significantly less than maxim range estimates, for a number of reasons. For example, drivers are often urged by car-makers not to charge to 100 percent or drive to zero-percent state of charge. Furthermore, real-world conditions are usually not ideal; weather conditions, age of the car and its batteries, driving style, payload, tire wear, the road surface, traffic, and many other factors all can reduce range.
- As a rate of range decline. In between charging sessions range is normally declining (even while parked). The rate of decline, however, can both increase and decrease. The average rate of this energy loss clearly impacts range. Just as an ICE car has range based on the volume of gasoline it can carry and the varying rate of gas used while driving/idling, a BEV has range based on the storage capacity of its high-voltage battery array and the varying rate of energy expenditure. As gas-mileage in an ICE car is affected by various conditions and driving behavior, there are a number of factors that affect the rate of battery-energy decline. The base-rate of decline during a single trip is probably determined initially by relatively-unchanging factors (like weight of the car, aerodynamics, and other engineering characteristics). But the rate of decline is also constantly varying with speed, headwind, incline, use of accessories, addition and subtraction of payload, and so forth. In general, the greater the average rate of decline the lower the ultimate range will be between charging sessions.
Why Want More Range?
It is a sad fact of life that there are very many (often fun, exciting, comfortable, interesting, convenient, or cheeky) things that hasten the decrease in electric-car range, while there are relatively few (and at that, usually boring, sedate, cautious, and dull) things that slow that inevitable decline.¹²
An electric car’s range budget is a constantly changing balance-sheet of energy stored onboard and rates of energy-expended while driving and parked. Maximum onboard energy storage is primarily determined by the size/volume/efficiency of the car’s high-voltage battery array. The ever-changing rate of energy expended is a pretty much a continuous (though varying) thing, even when the car is supposedly shut off; with many obvious and some unseen activities endlessly draining energy from the batteries.
Naturally, a primary expenditure of energy is the use of electrons stored in the battery to power the electric drive motor(s) while you are tooling down the road. That is unavoidable. Some electric cars weigh less, are more aerodynamic, or are otherwise more efficient. But they all use up energy that is translated into movement (and lost through friction and heat). But what additional factors sap energy and decrease maximum range?
Some of the things that further decrease range (in no particular order) include:
- Driving aggressively (e.g., jack-rabbit starts and rapid speeds).
- Towing.
- Off-road and winter conditions like traveling through mud, dirt, sand, and snow.
- Carrying a large payload (of people and things).
- Driving uphill and on twisty roads.
- Weather, including head-winds, precipitation, and low/high ambient temperatures.
- Power-sapping accessories (including especially energy-hungry gadgets like on-board refrigerators).
- Running the A/C and heaters.
- The so-called "vampire drain" from various optional settings and modes in onboard software (like Tesla’s notorious Sentry Mode; does that also include Gear Guard?) and from unseen/unknown car components.
- Certain wheel and tire designs and sizes—e.g., high-performance and off-road tires, and some non-stock sizes and designs.
- Tire pressures not at recommended levels.
- Auto-makers’ recommendations that cars with certain battery types not normally charge past 80% capacity (to increase long-term battery life).
- The natural aging of batteries and other parts.
- The sad fact that many estimated maximum range values are from the start seemingly inflated, calculated under absolutely perfect and difficult-to-duplicate laboratory conditions, or otherwise in no way indicative of true real-world conditions. (Not all car brands are equally guilty of this.)
- Driving smoothly and sedately at recommended speed limits.
- Sticking to smooth, well-maintained paved roads.
- Relying on effective/efficient regenerative braking.
- Managing long-term battery life (e.g., by not charging past 80%).
- Using factory wheels and tires maintained at recommended pressures.
- Performing routine maintenance.
- Using internal climate-control devices sparingly.
Somewhat like the value of most new cars as you leave the dealership, once you drive away from a charger the level of energy is definitely going to decline; sometimes slowly and sometimes quickly, but decline regardless and not increase until you can reconnect again to a charging source. (Someday, all electric cars may have to be Aptera-like and include effective solar panels to help maintain the state of charge. But the technology is not there yet for most BEVs, which are too heavy, too non-aerodynamic, or living in non-amenable areas, weather-wise.)
So what is a range-concerned electric-car enthusiast to do? Once you select the brand-model you prefer (based on various factors), I recommend that you get the specific car/truck with the greatest inherent range possible (that you can afford). This will send the message to car-makers that customers value range. And until electric car charging attains the three re-fueling objectives established some time ago by ICE cars—generous driving range, an abundance of easily-accessible fueling stations, and quick and easy re-fueling—critics will continue to have ammunition to disparage the (otherwise clearly important) switch from petroleum to electricity.
B. Lower Profile Tires
Often seen on high-performance sports cars, the modern incarnation of relatively lower-profile tire designs normally provide better handling and performance, and have become increasingly popular with customers desiring performance (or the appearance of performance) in many types and price-levels of cars (Reference). But lower-profile tires may provide such benefits at a cost—e.g., reduced ride comfort, increased likelihood of tire and wheel damage, more road noise, faster tire wear, and reduced mileage are not uncommon. Some wonder why Rivian promotes 22-inch wheel-tire sets at the expense of a 20-inch wheel-(34") road tire option that truly maximizes range and gives better ride comfort?¹³ Whatever the reason, it should not stop drivers desiring greater range from reasonable experimentation.
Figure 6. Side-by-side comparison of
lower- and higher-profile tires.
C. Speedometers and Tires
Accurate speedometer readings are an obviously desirable and important safety feature. Since about 1910 dashboard speedometers have determined the rate of vehicular speed by various mechanical and/or electronic means. Regardless of the mechanism, the size (specifically circumference) of drive tires can often influence speedometer and other readings, so speedometers are routinely calibrated/programmed to take into account the size of factory-provided, stock (OEM) tires.
Although a very common practice, for obvious safety and liability reasons most auto-makers discourage drivers from changing the size of OEM, factory-supplied wheels and tires. But manufacturers (like Rivian) sometimes offer their own optional wheel-tire sets for a particular vehicle that may differ enough in size to possibly require speedometer re-calibration when switching from one optional wheel/tire to another.
In these days of increasingly computerized cars, some onboard software has begun to allow drivers to switch from among factory-optional-only wheel-sets. (Tesla software is one such example.) I do not believe that Rivian onboard software provides that feature just yet. Instead, drivers must currently pay (~$150) to have their car software updated in order to return the speedometer to accuracy after installing certain new tire sizes. This analysis intends to avoid that cost and inconvenience.
D. Tire-Size Calculators
I don’t know about you, but I initially found tire sizes rather perplexing. For example, “275/65R20 LT.” What the heck does it mean?
I suspect that when new tires are needed the majority of consumers simply walk into a discount tire store and put their trust totally in the employees there. And in most instances maybe that is OK.
But when you have specific needs, a particularly valuable or specialized car, you really want the best outcome, and you don’t want to be pushed into buying this week’s overstocked tire model, just as with any other important (and expensive) decision it pays to do your homework ahead of time. Fortunately there is something called the Internet…
The numbers and codes embossed on the sides of tire can be interpreted with the help of many websites (for example here). They have to do with features such as the:
- various tire-size dimensions
- intended weight and class of vehicle
- inflation pressure
- load and speed indices
- special needs (e.g., rain, mud, and snow)
In this case we are particularly interested in the wheel diameter, and in the diameter and sidewall height of tires to be considered. As you may recall, diameter translates directly into circumference by using the formula C = 2πr (circumference equals two times “pi” times the radius). By the way, “π” is the Greek symbol for that elusive number “pi” and is (approximately) 3.14. Pi is the ratio of any circle’s circumference to its diameter.
But is there an easier way to compare tires that does not involve high school Algebra, creating spreadsheets, or breaking out the old Texas Instruments calculator? Yes.
Figure 8. Remember this?
Texas Instruments
hand-held calculator.
Many online sites provide convenient online tire-size calculators. Here are just a few:
- Calculator.net online tire size calculator
- Tacoma World online tire size calculator
- Discount Tires online tire size calculator
By entering the starting tire size (say 275/50R22--the current Rivian 22-inch performance wheel-set size) and a possible alternative (say 275/60R20--a 20” wheel and tire), you can pretty quickly compare diameter, sidewall height, circumference, and better yet, even true speed variations, thereby determining if speedometer re-calibration are necessary.
- Source -
Figure 9. "Inching-Up" is not strictly possible using
Rivian OEM wheels only. But this figure illustrates
in general how tire diameter can stay the same
while wheel diameter changers significantly (e.g.,
from 15" up to 18" in one-inch increments). The
trick is changing tire sidewall height ("profile").
Using an online tire-size calculator and a good list of Rivian-compatible tires will help point you in the right direction the next time tires need changing—especially if you feel the need for experimentation, with improved range as a goal for example.
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Footnotes
Footnotes
In the Body of the Text
¹ Alternate titles: “The Lone Ranger,” Open Range,” “Chasing Range,” “Range Finder,” “Free Range,”
“At Close Range,” “Full of Range,” “Road Range,” etc., etc. 
² My theory in a nutshell:
- Local/regional air quality, human health, and other factors will significantly improve with a shift from internal combustion engine (ICE) to battery-electric (BEV) vehicles.
- A timely switch to BEVs should therefore be encouraged.
- Although BEVs allow a new, novel convenience—easily charging overnight, at home--many drivers are unable to charge at their residence and/or must sometimes travel long distances requiring the use of a manufacturer’s or third-party charging stations.
- As we all remember, ICE cars traditionally enjoyed generous range, plus extremely accessible and quick fueling.
- To further encourage uncertain consumers to consider the switch from ICE to BEVs, we need those three critical BEV charging factors—range, fueling accessibility, and time to refuel—to continue to improve.
Ascend Quad Max.
⁴ That’s pretty good for a big, heavy, and not particularly streamlined SUV. It should provide
a practical real-life range in the mid- to upper-300s, perhaps.
In Tables
⁵ According to online tire guides (for example) at least 19 different All-Season and Touring
tires are available in the 275/65R20 size with adequate Load Capacity and other characteristics. Prices vary from $181 to $418 per tire, tread depth from 12/32" to 16/32". Interested readers are advised to check out descriptions and specifications (plus videos) on pertinent tire-store and tire-manufacturer's websites. Links to these are available on the tire guide websites (here and here), In particular, pay attention to tread design/depth and what reviewers say. I, myself, am initially interested in what may be a possible "Goldilocks" option (not too soft, not too hard, etc.)--the Continental TerrainContact H/T tire.
⁶ There appear to be no 21" tires that meet (load) requirements and maintain diameter/circumference. Plus, in this case it probably makes little sense to increase wheel size.
⁷ As others have noted, there are really only two available tire brand-models in this 275/55R21,
21" wheel-diameter size. Will the Michelin provide greater range? Unknown.
⁸ There are, maybe, five 275/60R20 tires with the right characteristics that are considered "all-
season" or "touring" tires. All have Load Indices of 116, which is acceptable. Prices range from $212 to $290; tread depth from 10/32" to 13/32". Manufacturers include Michelin Goodyear, and Yokahama. Whether it is worth the time and money to replace 21" wheels and tires with one of these 20" sets is unknown. (Money might be saved by purchasing used 20" Rivian wheels.) In comparison, in some cases range might conceivably be improved by replacing 22" wheels with 20" wheels and 275/60R20 highway or touring tires.
⁹ Only Michelin & Pirelli all-season tires with proper characteristics are available in this 275/55R21
size. (See also Footnote 7.)
¹⁰ This wheel-tire option is available from Rivian only on the Dual Standard SUV and pickup truck
versions. A greater number of tire options appears to be available in the 275/65R20 size.
¹¹ Certain tires in 275/65R20 and 275/55R20 sizes are available, might conceivably provide better
range, but would require speedometer adjustment.
In Appendices
¹² With the one exception of buying your car! That is one of the few things you can do that can
be both (a) fun and (b) able to increase range. Though arguably less exciting, another thing you can do may be replacing wheels and tires (hence the point of this post).
¹³ The answer may be that Rivian has just accepted things as they are and is just giving
customers what they want. (Plenty of other manufacturers do that—i.e., sacrifice ride comfort and mileage to provide automotive performance and fashion.)
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Additional References
Additional References
Some Rivian-Forums Posts & Threads
- Most efficient 20" tire?
- List of compatible tires (for each Rivian factory wheel diameter)
- Stock Rivian R1T Wheels Comparison (20" AT, 21" Road, 22" Sport) Range and Efficiency Test --by OutOfSpec
- Nokian 20" All Season Tires (One HT) - Thoughts?
- Affordable high efficiency 20" wheels and 33" tires options (275/60R20)
- !¿ Best 20” AT Tire for Range?!
- 20" Nitto Recon Grappler AT tires 25% more efficient than Pirelli OEM AT! The holy grail!
- Scorpion AS+ tire swap (from 20" Scorpion AT) - WOW big difference
- 20" tires and wheels -- "quiet" all-season touring tire recommendations ?
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