LR True Range -- Part II, Early Evidence

[03DSG]

I disagree. While some ICE cars can be driven significantly past zero miles remaining, others can’t. Some cars have a buffer to protect their fueling equipment (a good example of this is a new VW TDI that leaves one gallon of buffer in the tank because the high pressure fuel pump is cooled and lubricated by fuel - running too low will damage it).

New Teslas can often be driven past zero miles remaining. How far depends on the specific car. Aged Teslas sometimes cannot. Some 90 kWh owners have had their vehicles shut down with available miles still showing on the meter.

So my point is to be careful with generalizations. Newbies may take what you say and get themselves stuck.

My Escape shows empty and Zero miles remaining with 8 litres (2 gal) left in the tank. Same fuel pump issue. It will burn out if run completely dry.

 

[Big Earl]

Your talking about the past, I'm talking about the future. You named one ICE car that had some wired fuel pump. I referenced 30 years of common practice by drivers to drive 30 miles on E. So I disagree with you and your argument didn't sway me.

There would be nothing worse for Tesla then tons of photos of model 3s on flat beds because drivers pushed the limits. Not to mention the complaints after the first year and car losses 10 miles of range. Not everyone will educate themselves so Tesla has to protect them from themselves.

Cool. Be sure to let us know how far past zero you can go in your future vehicles. I really don’t understand the fascination (obsession?) with pushing the range envelope to the point of getting stuck or causing damage, but to each his own.

 

[Reciprocity]

Cool. Be sure to let us know how far past zero you can go in your future vehicles. I really don’t understand the fascination (obsession?) with pushing the range envelope to the point of getting stuck or causing damage, but to each his own.

By future, i meant model 3 and beyond. You and others keep taking about P85s and S60s that are not made anymore and where not mass market cars.

Don't hate the player, hate the game. I didn't force people to do ill advised things, but they do. I don't know if you have noticed, but most people are not that smart or just can't be bothered with learning how EVs work. So it's just good design to compensate for that.

 

[Big Earl]

By future, i meant model 3 and beyond. You and others keep taking about P85s and S60s that are not made anymore and where not mass market cars.

Don't hate the player, hate the game. I didn't force people to do ill advised things, but they do. I don't know if you have noticed, but most people are not that smart or just can't be bothered with learning how EVs work. So it's just good design to compensate for that.

I totally get what you’re saying and I agree with your sentiments about the average consumer. That said, I think building in a buffer is a slippery slope that can be counter productive. If the displays are accurate and zero really means zero, everyone will know what they’re dealing with and there should be no surprises. Of course, displays like Tesla’s rated miles can be misleading to those who aren’t EV savvy, especially in the winter.

My caution to prospective EV drivers is this: don’t count on being able to drive beyond zero miles remaining even if you have done it before, know someone who did it, etc.

 

[GSP]

Battery SOC remaining or rated miles remaining are not accurate to a fraction of a percent or mile. They can easily be off by several percent or several miles. If a car is found to have a "reserve" that is just the software erring on the conservative side. It will sometimes err the other direction, so it is not wise to drive to zero.

Even if the SOC estimation (all the software can do is to estimate) was always accurate to 0.1% it is not good for the battery to deep discharge it anyway (yes it will be ok if you plug in and charge it soon, but it still is a stressor for the cells).

Good for the pack or not, the best way to measure the capacity is to charge to 100% and immediately drive off, measuring the kWh consumed until the car no longer will move. Then get it on a charger right away to save the pack. The distance driven will depend on many factors, but the kWh delivered will be more consistent from time to time and car to car.

GSP

 

[gregincal]

Here's my contribution. It's my daily 60 mile round trip commute, and in good weather and normal traffic it was always pretty consistent in my Model S. It's pretty mixed driving. A little city, a fair bit of climbing over a windy mountain pass at 50-60 mph, some 70-75 mph freeway driving and some stop and go freeway driving (but the same mix of stuff each day). I generally used 285-290 wh/mile and about 1.05 rated miles per actual mile in my Model S. My 5 year old S85 had 249 rated miles (down from 265), so that's about 237 "real" miles (at least as I drive my commute).

Today in my Model 3 I got 248 wh/mile and about 1.09 rated miles per mile. We'll see how consistent that is in the coming days. That would translate to a real world range (for me) of 283 miles. Definitely a lot more than I had in my S. I'll post again when I get more numbers for my commute.

 

[EV-lutioin]

Here's my contribution. It's my daily 60 mile round trip commute, and in good weather and normal traffic it was always pretty consistent in my Model S. It's pretty mixed driving. A little city, a fair bit of climbing over a windy mountain pass at 50-60 mph, some 70-75 mph freeway driving and some stop and go freeway driving (but the same mix of stuff each day). I generally used 285-290 wh/mile and about 1.05 rated miles per actual mile in my Model S. My 5 year old S85 had 249 rated miles (down from 265), so that's about 237 "real" miles (at least as I drive my commute).

Today in my Model 3 I got 248 wh/mile and about 1.09 rated miles per mile. We'll see how consistent that is in the coming days. That would translate to a real world range (for me) of 283 miles. Definitely a lot more than I had in my S. I'll post again when I get more numbers for my commute.

Apparently the Model 3 has a 78.3 kWh battery (usable capacity), so based on that number, your range would actually be 316 miles at 248 Wh/mile.

 

[gregincal]

Apparently the Model 3 has a 78.3 kWh battery (usable capacity), so based on that number, your range would actually be 316 miles at 248 Wh/mile.

There's a bit of a disconnect between that and the reported rated miles at 100%. If it really does have a 78.3 kWh usable battery they are hiding rated miles somewhere.

 

[jerjozwik]

i am jumping on the 340 mile at 100% bandwagon.

 

[Electroman]

What?? Only 187 wh/mile for 22 miles?

All downhill?

 

[jerjozwik]

What?? Only 187 wh/mile for 22 miles?

All downhill?

that was including some from standstill WOT accelerations and 80+ passing maneuvers. i still have yet to do a grandma mode commute.

here is the elevation profile. drive to work is the same... except reversed.

 

[Agon]

That is impressive! I expect you dont use airconditioning or heating of any sort?

 

[jerjozwik]

That is impressive! I expect you dont use airconditioning or heating of any sort?

just the butt heater on 3.

 

[Electroman]

I am sure you can compete for high-efficiency driving hall of fame..

 

[jerjozwik]

today i broke 174 with a 213 full commute. that was including 2, 3 mile, show and tell drive arounds each getting at least two acceleration demonstrations, along with blasting up the Alameda onramp on my drive home. side note, this little car handles really f'ing good. and included a mile or so blast around all the fools clogging the 1 and 2 lanes when 3 and 4 were wide open...

50 miles for 11kWh.

 

[jerjozwik]

im pretty bad at science... drove the 3 today, but started from 266 rated miles. the car was sitting in my driveway yesterday and had vampire drained 6 miles which added to the kwh consumption. still, 207 for the day is not bad! was tiring for efficiency but it seems i was using up more on my drive home than normal. this is fun.

 

[gregincal]

im pretty bad at science... drove the 3 today, but started from 266 rated miles. the car was sitting in my driveway yesterday and had vampire drained 6 miles which added to the kwh consumption. still, 207 for the day is not bad! was tiring for efficiency but it seems i was using up more on my drive home than normal. this is fun.

It's all about speed. You took 46 minutes to go 22 miles, which is an average of about 30mph, which just happens to be the ideal speed for max range.

 

[jerjozwik]

It's all about speed. You took 46 minutes to go 22 miles, which is an average of about 30mph, which just happens to be the ideal speed for max range.

and? this is where i drive. my S is NO WHERE CLOSE TO THIS.

 

[omgwtfbyobbq]

It's all about speed. You took 46 minutes to go 22 miles, which is an average of about 30mph, which just happens to be the ideal speed for max range.

Only if someone actually goes 30mph the entire time. Lets say I'm driving a car with the defaults from ecomodder's power versus speed calculator(Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com), and have a 20 miles commute and...

1) I travel 10 miles at 80mph and 10 miles at 20mph, for an overall average of 32mph (20 miles/(.125h + .5h)). Energy consumption at 80mph is about 250Wh/mile, and at 20mph about 40Wh/mile, for an average of 145+Wh/mile.

Or...

2) I travel all 20 miles at 32mph, and my energy consumption is 60+Wh/mile.

Same average speed, very different energy use. Miles per hour is a function of speed, while Wh/mile is strongly a function of speed squared. The more our range of speeds diverges from our average speed, the higher our energy consumption will be even if the average speeds are the same.

 

[omgwtfbyobbq]

and? this is where i drive. my S is NO WHERE CLOSE TO THIS.

What's your S at?