Performance not getting 310 miles promised

[SammichLover]

I have also been driving EV's since 2011 and I really do believe that counts for something. Knowing when to lift and let Regen do its thing, how to accelerate gradually up to speed, looking way ahead on the highway to gradually slow down when traffic does for max Regen? All of those things collectively pay huge dividends. I can also drive the car like I used to drive my Ferraris -- and that reduces efficiency by at LEAST 100 Wh/mi...BOTH ways of driving are tremendously enjoyable and have their time and place and that is what I absolutely adore about my M3P...it CAN do both.

It is pretty dramatic how much you can improve Wh/mi while maintaining the same top end cruising speed by looking further ahead, avoiding friction brake use, keeping acceleration rates lower, and carrying more speed smoothly through corners for less and smaller slowing/accelerating cycles.

<edit> And frugal HVAC management, including installing heat blocking film in sunny climates.

 

[AlanSubie4Life]

I have also been driving EV's since 2011 and I really do believe that counts for something.

It does help I am sure. But overall, it is not that complicated to be efficient, and it may be that you are blessed with a car with very little toe-in, slightly more efficient drivetrain, etc. There is no fighting the aero though.

As I said, I really haven’t had experience with a reasonably flat drive yet. San Diego is extremely hilly so there is rarely an opportunity. Maybe it will do better than I think! We’ll see. At least I have a reference point with the P3D Stealth now.

 

[Jedi2155]

The EPA documents seem to suggest about 79kWh before it is dead.

https://iaspub.epa.gov/otaqpub/display_file.jsp?docid=46585&flag=1

The meter in the car may read a few percent low. Even for no sitting after a charge and just driving I can’t get it to compute to even 75kWh normally...

Your numbers seem about right; I assume you were moving pretty quickly (70+?)

About 68 mph average. I've never seen 75 kWh+ since 1st day I got my car even if I have zero AC etc. I really don't think Tesla allows us to use 100% of the pack capacity. The 78270 Wh number provided by the EPA is probably the freshest battery they can obtain. The actual design capacity of the pack is 80,500 Wh however based on my 6 months of driving (i've been using TeslaFi since my first week of owning the car), I pulled all the drive logs and never saw a capacity estimate much beyond 70-72 kWh over a reasonable length of drive.

That being said, there could be other reasons such as the kWh used as displayed by the trip meter doesn't account for all the auxiliary loads (AP computer, HVAC etc.) and only motor loads which could add up to 5+ kWh over a long drive.

 

[UngaBunga1989]

It does help I am sure. But overall, it is not that complicated to be efficient, and it may be that you are blessed with a car with very little toe-in, slightly more efficient drivetrain, etc. There is no fighting the aero though.

As I said, I really haven’t had experience with a reasonably flat drive yet. San Diego is extremely hilly so there is rarely an opportunity. Maybe it will do better than I think! We’ll see. At least I have a reference point with the P3D Stealth now.

I know that it is not that complicated to be efficient, but it does require a learned set of skills and attention to detail while driving. I doubt that my car is anything special (by the way it is a full-blown P3D+, not the Stealth version). As I mentioned earlier, the difference between my wife's efficiency and mine on our 2016 Volt is roughly 35% (I can routinely get 68 miles on a charge and she gets around 50). That would put her driving style well up into the 325-340 Wh/mi range on the Tesla. The 250 Wh/mi is in the P3D+ under normal driving conditions with an efficient driving style. That does NOT mean that it should always be driven that way -- it's just too darn fun to press the go pedal...hard!

Good luck on your trip...looking forward to seeing what you do!

 

[AlanSubie4Life]

About 68 mph average. I've never seen 75 kWh+ since 1st day I got my car even if I have zero AC etc. I really don't think Tesla allows us to use 100% of the pack capacity. The 78270 Wh number provided by the EPA is probably the freshest battery they can obtain. The actual design capacity of the pack is 80,500 Wh however based on my 6 months of driving (i've been using TeslaFi since my first week of owning the car), I pulled all the drive logs and never saw a capacity estimate much beyond 70-72 kWh over a reasonable length of drive.

That being said, there could be other reasons such as the kWh used as displayed by the trip meter doesn't account for all the auxiliary loads (AP computer, HVAC etc.) and only motor loads which could add up to 5+ kWh over a long drive.

In order to get the EPA value, you would need to drive for at least 6 miles past “zero”, because that is what they do in the EPA test. They drive until it is unable to comply with the test. So that is part of the discrepancy.

Otherwise, In the EPA test they put current clamps in 3 places (though not sure more than one is necessary). For the in-car meter, it’s actually pretty hard to measure current; I don’t think they use a current clamp though I could be wrong. Not sure exactly how they come up with the number, but I suspect the meter is part of the BMS system, so in the end it’s an estimate. Maybe someone more knowledgeable here could comment. Of course, it does not include any losses when in park, or vampire losses, so that is another source of error.

 

[AlanSubie4Life]

I know that it is not that complicated to be efficient, but it does require a learned set of skills and attention to detail while driving

Sure, part of what I was saying though is that on a freeway there is little to be done about the aero except to draft (or go slower). And none of these other techniques (except accessory use) come into play if there is no slowing. If you were using TACC (which presumably you are not), about what following distance (which number) would you say you are typically at on the freeway?

 

[famoruwa]

Charged my M3P up this past weekend and it showed 309 at full charge. Obviously driving behavior can alter whether or not that distance will be actually reflected but it seems accurate to start. With regen and moderate driving, it should be feasible.

 

[Paddy3101]

I can hit(or beat) the 250Wh/m on my commute which is 35 miles each way, San Diego area, hit that this morning. Let the car drive 30 of the 35 miles. Does depend of he flow of traffic. If it's busy, it keeps the speed down, especially up the hills which helps. Not in the express lanes, so speed it limited by the traffic.

Got the climate set to 68, which is about outside temp. TAAC was set to 75 with distance set to 4. Mostly slower than 70 though. Tires are at 40 (need a little air adding). NoA set to Mad Max. Starting at 90% which shows as 274 at the moment. Can get that both ways, starting and ending at the same altitude.

Could probably better that IF I drove it myself, and concentrated, and kept the speed down. However, I don't usually, as range isn't a problem.

Biggest thing thing to increase efficiency, with either electric or gas, is to just 'let the car run'. Give it some space so you don't need to be constantly correcting the speed. Same with the steering. The less input you give the car, the more efficient it will be.

 

[afadeev]

Is there anyone having issues with Performance range? After 1,000 miles driven and 10,000 driven RWD, I am not getting even 200 miles I guess... while they advertise 310 miles.

Charged my M3P up this past weekend and it showed 309 at full charge. Obviously driving behavior can alter whether or not that distance will be actually reflected but it seems accurate to start. With regen and moderate driving, it should be feasible.

I am always amused at people complaining about EV range. Someone even tried to sue Tesla over observed range.
That never seams to be a "thing" with ICE cars. I've never heard of anyone complaining that their cars go too short on a gas tank, or their MPG is way lower than advertised while spanking the car on track.

The range is just an estimate, based on current state of battery charge, and past discharge rate per mile.
As you driving speed, ambient temps, road surface, road grade, frequency of accelerating/declarations events continues to evolve, so will the discharge rate.

I realize that translating battery SOC rates into miles is easier for an average person to comprehend, but doing so introduces the inevitable error of predicting the future discharge rates. Which is an impossible task to complete with any degree of precision.

I seam to average 280 kWh/mile this time of the year (M3P), so assuming 72 kWh usable fully charged battery, I expect ~257 miles of driving to empty. Which I will never actually observe, since I will never drive to empty, nor will my next drive be an exact replica of the average consumption pattern of all of my previous drives.
So I figure, ~250 +/-20%.
Unless I go uphill, or am filling frisky, or ambient temps drop or rise by more than ~20F.

Yet people still get upset when their actual observed driving range continues to deviate from that which was prognosticated.



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[MP3Mike]

I am always amused at people complaining about EV range. Someone even tried to sue Tesla over observed range.
That never seams to be a "thing" with ICE cars.

I haven't heard about Tesla being sued, but I know someone is currently suing GM for the range on the Bolt EV in cold weather.

And it has been a thing in the past when ICE manufacturers lied, or rigged, their EPA numbers. It just hasn't been a thing for range lost based on use, because it doesn't have the same penalties. (When 80% of the energy is waste heat, using 10% more to move you isn't as noticeable.)

 

[AlanSubie4Life]

I can hit(or beat) the 250Wh/m on my commute which is 35 miles each way, San Diego area, hit that this morning.

Sounds pretty good. What was true average speed over the entire trip? Not too surprising to be able to do this in traffic on the freeway below 65mph though, even with a P3D+. No significant aero losses in that case.

 

[Paddy3101]

Sounds pretty good. What was true average speed over the entire trip? Not too surprising to be able to do this in traffic on the freeway below 65mph though, even with a P3D+. No significant aero losses in that case.

I'll set a trip on the way home.

It CAN be done. I CAN also significantly shorten the range quite easily.

 

[UngaBunga1989]

Sure, part of what I was saying though is that on a freeway there is little to be done about the aero except to draft (or go slower). And none of these other techniques (except accessory use) come into play if there is no slowing. If you were using TACC (which presumably you are not), about what following distance (which number) would you say you are typically at on the freeway?

My following distance varies between 2 and 3.

 

[AlanSubie4Life]

Charged my M3P up this past weekend and it showed 309 at full charge. Obviously driving behavior can alter whether or not that distance will be actually reflected but it seems accurate to start. With regen and moderate driving, it should be feasible.

Let us know! I have not seen a single report yet of anyone achieving 300 (or even 290) miles with a P3D+ on a single charge with stock tires. (Nor do I expect to.) This is the relevant metric for range. (We're not only talking about driving efficiency here, though obviously that is the major factor for range!) For example, you can have excellent driving efficiency (below 225Wh/mi, say - though that would be hard in a P3D+), and still only get 250 miles out of a full charge - depends on the timeframe. But those cases we don't usually care about because that is (usually) not a range issue.

 

[Paddy3101]

34.5 miles in 50 minutes, avg 248 Wh/mi. this morning. 222Wh/m for last 30. Last 29.8 is freeway. 7:30 am this morning.

Can't say I would drive at that speed on a clear road. But in traffic on a commute this morning, that's what I got.

 

[SD_Engnr]

34.5 miles in 50 minutes, avg 248 Wh/mi. this morning. 222Wh/m for last 30. Last 29.8 is freeway. 7:30 am this morning.

Can't say I would drive at that speed on a clear road. But in traffic on a commute this morning, that's what I got.

That's impressive. Is this East to West on the 8?

 

[Paddy3101]

That's impressive. Is this East to West on the 8?

North South (78, 15, 163). Ending close to the Service Center. Also on NOA since getting on the 78 (apart from lane merge at 78->15)
Have had sentry on, since I parked up, so lost a few miles there this morning.

Main influence here is traffic, and hence speed (avg 41.4 mph). You can see the hills/traffic in the trace.

 

[SD_Engnr]

North South (78, 15, 163). Ending close to the Service Center. Also on NOA since getting on the 78 (apart from lane merge at 78->15)
Have had sentry on, since I parked up, so lost a few miles there this morning.

Main influence here is traffic, and hence speed (avg 41.4 mph). You can see the hills/traffic in the trace.

Ah, ok. That makes sense with your average speed.

 

[Feathermerchan]

41.4 mph is very little wind resistance. All tires.
With OEM setup (20", 4S tires) I was doing good to stay under 300 or 290. Now with 18" forged and 245/45 Primacy, I am more like 240-250.

 

[Paddy3101]

41.4 mph is very little wind resistance. All tires.
With OEM setup (20", 4S tires) I was doing good to stay under 300 or 290. Now with 18" forged and 245/45 Primacy, I am more like 240-250.

That's with 20" 4S tires. Also, was just what I got this morning, not trying or anything, not knowing was going to post it here. So a blind trial result if you like.

Lower Average speed helps, but speeding up 0-75-0-75-0 etc does the opposite. Don't know exactly what the balance would be.

So I believe the rated range is achievable. The EPA highway average speed is 48mph and maxing out at 60. The City section averages at 20mph. So the 41.4 mph average is somewhat comparable to the EPA average speed.

Had air-con on auto-68F (but probably not doing much) and radio, and just letting NOA do it's thing, so not hyper-efficient by any means.

So I believe the car CAN get the range indicated, but would be pretty bored driving 310 miles under those conditions if doing a road-trip.