Lower Range?

[ajdelange]

Well not much more. I grant you I have ended trips with more in the battery than I set out with and had the projected range display show 999 miles but obviously that was coming down a mountain. At 4% better than EPA I am in the 90th %ile of X drivers. The highest number on the histogram is 135%. Now 35% of 400 is 140 miles and I guess that might be considered "much" more.

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[electruck]

...or more (much more) if you aren't doing highway speeds.

Even that depends heavily on your driving style and conditions. Just as with an ICE vehicle, a lead foot will greatly increase energy consumption.

 

[ohmman]

At 4% better than EPA I am in the 90th %ile of X drivers. The highest number on the histogram is 135%

Assuming the sample used to generate the histogram is representative of the wider fleet. I question a lot of these TeslaFi stats because there's a little selection bias in them (not necessarily with regard to range, but other factors) and the count is relatively low compared to the actual fleet on the road. For instance, I tow my trailer and that gets dumped to TeslaFi, showing thousands of miles of consumption at 600Wh/mi+. But my non-towing average is well better than EPA.

Still, you're probably in the ballpark overall. I have always outperformed EPA on my cars, but I live in a temperate climate and don't regularly drive on highways.

 

[ajdelange]

People familiar with the methods of statistical analysis always ask themselves certain questions when approaching any result of such an analysis. And probably the first one is "Is the sample representative of the population?" It is probably better posed as "How representative of the population is the sample?" as no sampling technique is perfect (except using the population as the sample). In this particular case we can start by observing that as California has far and away more Tesla drivers than any other state that it is over represented and thus that these statistics (not from TeslaFi) are more representative of what a California driver might expect than one from Manitoba.

So the conclusion drawn from this histogram, that driving style won't gain you much more than EPA range, should be considered in light of what we know from our experiences and what we have learned from those of others and, if one is so disposed, from the physics. We all know that a headwind, hilly terrain, driving fast, carrying lots of weight, accelerating out of every stoplight like A. J. Foyt, rain, snow, gravel, frequent stops, irregular speed, cold weather, hot weather (using the A/C), towing and driving with the windows open will reduce range. Some of these conditions, or especially a combination, will reduce it dramatically. OTOH there are very few scenarios we can come up with that increase it dramatically. If you work for an anvil maker located at the top of a mountain and your job is to deliver the product to distributors in the valley you will get dramatically better range than EPA. Other than that tailwinds are about the best we can hope for. Even slowing below EPA speeds doesn't help - consumption actually goes up.

The histogram shows users with efficiencies as low as 40% meaning 160 miles range for a car rated 400 EPA. If those drivers stopped doing whatever it is they are doing to get such terrible mileage (perhaps delivering anvils from a manufacturer in the valley to a distributor at the top of a mountain) they would get closer to the rated mileage for their vehicles. That means picking up 240 miles. That is much better than 160 so perhaps that what was meant.

 

[ja_kub_sz]

Does anyone know if Rivian's quad motor wheel based propulsion system will be better for range or equal to the dual motor Tesla set up?

Tesla claims the two motors is better for range despite the added weight compared to the single motor.

My concern is other EV manufacturers aren't anywhere near Tesla's efficiency when it comes to pack size and range. So Rivian using 180kwh pack with a heavier vehicle and being less aerodynamic would that substantially reduce the anticipated range?

400 miles would be nice, but with my Tesla I would get like 75% of what the stated range would be (+/-10% for weather).

Either way... Not taking any chances and going with the 180kwh pack.

 

[DucRider]

Tesla uses everything they can to maximize the official EPA number (Model S LR+, Model X LR+ are prime examples). Some "tricks" are opening up the top of the pack (hence the recommendation to only charge to 90%), using a detailed profile on the 5-cycle test to allow less derating of the test results, lots of regen enabled on the test.
Taycan owners and 3rd party reviewers easily exceed the EPA combined number by a significant amount with normal driving (high freeway speed, no hyper-miling techniques). Speculation is that their 2 speed rear differential never shows it's full advantage at the relatively low speeds of the EPA testing.
What the Rivian number will be and how accurate it is under typical real-world driving conditions is an unknown for the time being. We'll see the EPA number first, then only after a bunch have hit the road will we get owner feedback. In between will likely be some press/media tests and reviews that may also shed some light on the accuracy of the EPA number for the Rivians.
Bottom line is that most drivers will likely be able to exceed the EPA range given similar conditions to the testing (moderate temps, mix of city and lowish speed freeway), but for most those conditions are not the norm (hence the derating of test results for the Monroney).

 

[ajdelange]

Does anyone know if Rivian's quad motors wheel based propulsion system will be better for range or equal to the dual motor Tesla set up?

If someone does it is not I.

Tesla claims the two motors is better for range despite the added weight compared to the single motor.

You can be sure Tesla has studied, simulated and tested the two approaches in order to come to the conclusion they did. The advantages of two motors are that each can, for example, be geared slightly differently so that one is most efficient in one speed range and the other in another. Then by switching which motor carries most of the load one can stay highly efficient as speed varies. The other advantage is that splitting the load during heavy demand allows half the current to each of two motors which means half the losses related to current squared and so on.

My concern is other EV manufacturers aren't anywhere near Tesla's efficiency when it comes to pack size and range. So Rivian using 180kwh pack with a heavier vehicle and being less aerodynamic would that substantially reduce the anticipated range?

Well Lucid is expected to give Tesla a run for its money but you can be sure that each manufacturer, including Rivian, has studied, simulated and tested his design before going to production. Tesla has more resources than any of the others at this point so you can argue that overall they are probably ahead of the pack, But the spread isn't great and it is ephermeral for sure.

400 miles would be nice, but with my Tesla I would get like 75% of what the stated range would be (+/-10% for weather).

That's very likely of function of where, when and how you drive. I and at least one other poster on this forum generally get better than the EPA performance. It is probably fair to say that you will get about 75% of the EPA range on the Rivian too. But is this going to be a problem?

Either way... Not taking any chances and going with the 180kwh pack.

Standard advice: buy the biggest battery you can comfortably afford.

 

[ja_kub_sz]

If someone does it is not I.

You can be sure Tesla has studied, simulated and tested the two approaches in order to come to the conclusion they did. The advantages of two motors are that each can, for example, be geared slightly differently so that one is most efficient in one speed range and the other in another. Then by switching which motor carries most of the load one can stay highly efficient as speed varies. The other advantage is that splitting the load during heavy demand allows half the current to each of two motors which means half the losses related to current squared and so on.

Well Lucid is expected to give Tesla a run for its money but you can be sure that each manufacturer, including Rivian, has studied, simulated and tested his design before going to production. Tesla has more resources than any of the others at this point so you can argue that overall they are probably ahead of the pack, But the spread isn't great and it is ephermeral for sure.

That's very likely of function of where, when and how you drive. I and at least one other poster on this forum generally get better than the EPA performance. It is probably fair to say that you will get about 75% of the EPA range on the Rivian too. But is this going to be a problem?


Standard advice: buy the biggest battery you can comfortably afford.

Thanks a ton for the response!

 

[DucRider]

Anyone that want to dig a bit (or a lot) deeper about how different motors and gearing can change vehicle performance attributes (and isn't afraid of technical details) might find this interesting:
https://www.cascadiamotion.com/evbot

Allows you to configure a theoretical vehicle with various versions of their motors and inverters. You can select number and types of motors per axle, gearing ratios, voltages, battery modules, etc. If you dig deep, you can find torque curves, etc

Local company (now a division of Borg Warner) that we work with at shows and on other projects. They've done numerous projects ranging including one-off Pikes Peak racers, the Chevrolet eCOPO big block replacement, Freightliner Class 8 trucks.

They offer some of their motors as either series or dual wound witht he result of difernt torque and power curves. It gets even more interesting if you put that in a dual stack motor (2 motors on one output shaft) with different winding methods. This allows you to select (and vary) the motor characteristics to be most advantageous for you desired power requirement for a specific circumstance (freeway vs city, acceleration vs efficiency, etc)

This spec sheet shows the different torque and power characteristics with the different winding options for one of their motors:
https://www.cascadiamotion.com/images/catalog/remy-pds---hvh410-075-sheet-euro-pr-3-16__5_.pdf
You can also see the efficiency "sweet spot" for one configuration in the graph at the lower left of the spec sheet

This spec sheet shows the dual stack version with 2 of the above motors:
https://www.cascadiamotion.com/images/catalog/DataSheets/DS-410-075.pdf
I believe this is what was used in the eCOPO Camaro project

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