Efficiency

[goldburger]

It seems any sort of elevation gain destroys my efficiency, and it doesn't get made up enough in regen/descents.... i've been able to push my lifetime efficiency (6k miles) to 2.06, and my regular daily efficiency ends up around 2.1 or so.

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[MRivian]

I recently got my R1S with 21" wheels. I did a test drive today in All Purpose mode to check the efficiency. Didnt accelerate hard the entire trip and it was all on local roads in 70F weather. Surprised at how bad the efficiency was at 0.88mi/kwh. Also, if you do the math on the distance I traveled divided by energy used it comes out to 0.76mi/kwh. Any reason why the efficiency is so low and the difference in the Calc?

 

[Budman]

I will direct folks to this thread I started showing the efficiency from a large data set I created on many repeats of the same 165 mile trip.

https://www.rivianforums.com/forum/...ture-and-bike-rack-vs-no-bike-rack-data.8782/

i have found this efficiency behavior to be consistent over the one year and 20,000 miles I have put on the R1T.

The efficiency is very repeatable and as advertised when doing long trips. On short trips it is very erratic In my experience. In my opinion you should not cast judgement on the true highway range/efficiency until you have driven around 25 miles at steady speeds.

 

[Lizardo]

I recently got my R1S with 21" wheels. I did a test drive today in All Purpose mode to check the efficiency. Didnt accelerate hard the entire trip and it was all on local roads in 70F weather. Surprised at how bad the efficiency was at 0.88mi/kwh. Also, if you do the math on the distance I traveled divided by energy used it comes out to 0.76mi/kwh. Any reason why the efficiency is so low and the difference in the Calc?

i run 21s with running boards on R1T. ~7500 miles. Avg 2.3-2.4 mi/KwH. 99.9% all purpose mode. Driving patterns matter ( hard accelerations). Nothing kills efficiency more than standing still in drive( traffic, drive through at Starbucks, etc).

 

[WSea]

i run 21s with running boards on R1T. ~7500 miles. Avg 2.3-2.4 mi/KwH. 99.9% all purpose mode. Driving patterns matter ( hard accelerations). Nothing kills efficiency more than standing still in drive( traffic, drive through at Starbucks, etc).

Camp mode also drops the eff number. Arrived wtih trip eff at 2.23. left after 2 nights and the trip eff had dropped down to 1.8 something. AC outlets on the whole time running a cooler and a few other items

 

[BrentInCO]

I've had my R1S for 12 days. Most days I've only driven short distances -- 2-3 mile trips and my efficiency numbers look abysmal -- around 1.7-1.9 mi/kWH. On some longer drives it hovers in the 2-2.2 range. This is in the Bay Area which currently has moderate weather (44-64F) in All-Purpose mode, Standard ride height, Soft suspension, Standard regen.

The best I managed (during a 10 mile trip) in 68F weather with climate control off driving 60mph in conserve mode was in the 2.8-3 mi/kWh range.

Today, I tried barely got 2mi/kWh cruising in conserve mode on the freeway at 65-70mph with climate control set to 70F and outside temperate around 60-62F.

I really haven't figured out what is impacting range so much. The difference between 2, 2.4 and 3 mi/kWH is huge. I have no idea how someone could get 2.38mi/kWh in All-Purpose mode, which is what would be needed to get the EPA range (321 miles with 135kWH battery).

What has your experience been?

I've had my R1S for 4 months, more than 8k miles, 2.05 mile/Wh which includes driving all over Colorado, dozens of mountain passes, which would include a mix of Conserve mode on highways (tends to improve range 10% or more). Strictly City driving (no mountain passes) the last ~1,200 miles I'm at ~2.4, in All-Purpose. Far better than I expected.

 

[MRivian]

Thanks for all the answers. I'll reset and try again on a longer drive to see whether this is persistent.

I'm thinking the efficiency hit may be because the car was also sitting in the garage for three days and lost about 10% battery. Maybe that was included in the mi/kwh Calc.

 

[MaskedRacerX]

I've had my R1S for 4 months, more than 8k miles, 2.05 Wh/mile, which includes driving all over Colorado, dozens of mountain passes, which would include a mix of Conserve mode on highways (tends to improve range 10% or more). Strictly City driving (no mountain passes) the last ~1,200 miles I'm at ~2.4 Wh/mile, in All-Purpose. Far better than I expected.

That 2.4 is actually miles per Wh, i.e., if you have a 135kWh battery, your range is 2.4 x 135 = 324 miles.

The other efficiency value often used is Wh/mile. If you take your 2.4 miles/Wh and do this:

(1 / 2.4) x 1000 = ~417

That's your Wh/mile (which is about that I see reported pretty often around here for more general street use).

 

[goldburger]

I've had my R1S for 4 months, more than 8k miles, 2.05 Wh/mile, which includes driving all over Colorado, dozens of mountain passes, which would include a mix of Conserve mode on highways (tends to improve range 10% or more). Strictly City driving (no mountain passes) the last ~1,200 miles I'm at ~2.4 Wh/mile, in All-Purpose. Far better than I expected.

LOL 2.4 with AT's in the mountains of Colorado. I hate how much I think about my efficiency.

I live in the foothills of Los Angeles so going home is a positive grade. I end my daily efficiency after 80 miles between 1.9 and 2.09 and a 23mph average speed. Lifetime somehow got bumped to 2.15 I think because I've been using the AC less.

 

[ch33rio]

R1T, 22in sport wheels, high regen, about 1k miles on the odo.

It usually starts out pretty bad, like <2 mi/kwh for the first 5 minutes of driving. I suspected this was due to the battery needing to warm up. Work commute is about 6.2 miles each way (in town), i get about 2.5-2.6mi/kwh. On longer trips, about 20-30 mi each way(mixed freeway ~70-75mph and some in town driving <50mph), i get 2.75-3+ mi/kwh AP mode. 3+ mi/kwh is pretty easy if i drive in conserve. I live in Houston, so AC on the coldest setting and sometimes the seat coolers running.

The trip readings will never be accurate over the course of a day b/c the vampire drain will throw off the mi/kwh efficiency. Since my work commute is so short, I may only use about 5 kwh/day total for driving, but the vampire drain adds another ~1.0-1.2 kwh on the trip meter so the next day my 2.5-2.6mi/kwh drops to 2.0-2.1. When i'm in the office, it consumes about 400wh while parked over an 8 hr period and ~15-20 gg recordings.

 

[IslandTreeHugger]

I've had my R1S for 12 days. Most days I've only driven short distances -- 2-3 mile trips and my efficiency numbers look abysmal -- around 1.7-1.9 mi/kWH. On some longer drives it hovers in the 2-2.2 range. This is in the Bay Area which currently has moderate weather (44-64F) in All-Purpose mode, Standard ride height, Soft suspension, Standard regen.

The best I managed (during a 10 mile trip) in 68F weather with climate control off driving 60mph in conserve mode was in the 2.8-3 mi/kWh range.

Today, I tried barely got 2mi/kWh cruising in conserve mode on the freeway at 65-70mph with climate control set to 70F and outside temperate around 60-62F.

I really haven't figured out what is impacting range so much. The difference between 2, 2.4 and 3 mi/kWH is huge. I have no idea how someone could get 2.38mi/kWh in All-Purpose mode, which is what would be needed to get the EPA range (321 miles with 135kWH battery).

What has your experience been?

I'm having trouble understanding how the R1S with a 0.28 cd and less weight has lower efficiency than the R1T with a 0.30 cd, especially since the R1T had no tonneau cover and the trapped wind in the bed likely caused the cd to increase even higher. I had my R1T from Jan '23 to Dec '23 and averaged 2.17 m/kWh and that's with Hwy speeds averaging 85-90. I traded the R1T for the long-awaited R1S, same 22" tires, 4-motor Adventure etc, but my efficiency average is 1.93 and temps in Dec in Florida were lower with less A/C needing to cool down than in the Florida Summer heat. Driving on local 4-lane by-ways, trip efficiency indicates as low as 1.47 m/kWh averages. How is that possible? Is something blocking/breaking/mal-adjusted?

 

[mkg3]

I'm having trouble understanding how the R1S with a 0.28 cd and less weight has lower efficiency than the R1T with a 0.30 cd, especially since the R1T had no tonneau cover and the trapped wind in the bed likely caused the cd to increase even higher. I had my R1T from Jan '23 to Dec '23 and averaged 2.17 m/kWh and that's with Hwy speeds averaging 85-90. I traded the R1T for the long-awaited R1S, same 22" tires, 4-motor Adventure etc, but my efficiency average is 1.93 and temps in Dec in Florida were lower with less A/C needing to cool down than in the Florida Summer heat. Driving on local 4-lane by-ways, trip efficiency indicates as low as 1.47 m/kWh averages. How is that possible? Is something blocking/breaking/mal-adjusted?

There are so many variables, it's difficult to pin point why the efficiency is much less. The only way to get an apple to apples comparison is to have the same driver drive the same distances and route during the similar environmental conditions. I think your case is pretty close though.

Also, I don't know where the R1S Cd 0.28 came from but I highly doubt its that, when aerodynamically tailored SUVs run about 0.38~0.45 range. At best, it would be equal to the truck's 0.3 (that's w/tonneau closed).

For R1S, there is a huge separated flow behind the rear hatch/tailgate that's much worse than truck w/tonneau closed (there is a smaller separated airflow behind the cab helped by the small roof split spoiler, then another small separation after the tailgate of the truck). Probably would help to put a row of vortex generators (VG) at the edge of the roofline and force the air downwards by having an extension to guide the airflow. I think VGs will do most of the improvement.

My R1S over 5k miles, averages just over 2.1 miles/kWh. Most freeway is driven in All purpose at 75~80 mph, which probably are 70% of the total miles.

 

[HaveBlue]

Too many variables on driving style, not to mention that we don't know what vehicle config the OP has. I have also noticed that constant throttle seems more efficient than constant speed. The ACC and hwa seem much less efficient constantly slowing and speeding up from cars in front or hitting hills. The numbers seem to dip for me when I turn that on at the same speed I was driving manually. I think if you are a smooth driver it's less sickening for passengers as well unless acc doesn't encounter much traffic. Then again, acc can keep you from speeding too.

Short trips means the cabin has to get warmed or cooled each time from ambient. Longer trips also amortize that penalty.

 

[jkahlon]

Personally speaking I enjoy the vehicle driving experience and not worry too much about efficiency. Would agree with the feedback.

The one time recently this became critical was on a trip to Joshua Tree National Park. Had the family with me went in with too few miles, the park is extremely large and every regen mile counted. There is no cellular in the park period.

The learning was you can maximize the mileage by driving slow by careful watching the green/blue curve on the dash to ensure you are mostly at par or in the green. In the park it is possible as you cannot do more than 40 m/h due to drops and turns. So you can babysit and optimize your range if you need to. We were celebrating every mile gained the entire way back.

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