sorry, I maybe got you wrong.. with "except friction braking" you mean that friction braking is more efficient than regen braking? I assume that regen braking is more efficient if you come to a full stop (and need the full stop) without the need of the friction brake. Don't you think so?
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Performance not getting 310 miles promised
- Thread starter Dan_LA
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sorry, I maybe got you wrong.. with "except friction braking" you mean that friction braking is more efficient than regen braking? I assume that regen braking is more efficient if you come to a full stop (and need the full stop) without the need of the friction brake. Don't you think so?
I have also struggled to get anywhere near the rated range with my P3D+ I tried these tires and have had some good numbers with them, similar to what others show at 265 wh/mi. I have yet to get the rated range, but once spring comes I will try again. Currently running https://www.americastire.com/buy-tires/nankang-tire-ns-25-a-s-uhp/p/41138
One thing I don't see mentioned is the quality of the road surface. Perfect tarmac interstates seem to do much better than the heavily grooved concrete highways. I see 20-30 wh/mi difference between the best and worst roads.
As far as braking goes, its best to just coast. Coasting to a stop, then using the friction brakes from 5 mph will get best range. If you want best range, set acceleration mode to chill, and regenerative breaking to low. Using Regen will always be worse than coasting.
The biggest differences to range I think are temperatures below 40F, Average speed, and heater use.
One thing I don't see mentioned is the quality of the road surface. Perfect tarmac interstates seem to do much better than the heavily grooved concrete highways. I see 20-30 wh/mi difference between the best and worst roads.
As far as braking goes, its best to just coast. Coasting to a stop, then using the friction brakes from 5 mph will get best range. If you want best range, set acceleration mode to chill, and regenerative breaking to low. Using Regen will always be worse than coasting.
The biggest differences to range I think are temperatures below 40F, Average speed, and heater use.
@Perry -Unless its your intention to mislead people you should also show them the wh/mi of the drive. From your previous posts, you are one of the hardest street drivers I have met. 500-700 wh/mi is how you get this range lol. I am pretty sure you know this, but your lack of mentioning it here misleads others. You love to go fast, which is great and all but obviously flooring it out of the corner, then max braking, rinse repeat will chew up a lot of power. Especially if you realize that the traction control system design uses a lot more power when wheels are slipping due to poor tires. Last I knew you were running the stock 18s, but I imagine those are almost dead. Even just switching to good rubber would in your very rare case increase that range I think lol.
I have not calculated but on my trip most of the charging was done when I'm around 70-80mi left on the battery. I was very conservative and only charged up to 290.
I don't know how I'd survive in a T-X with any wheel size since the consumption would be greater.
gilscales
Banned
This would not matter as you are only charged for kW not by time, in CA the price is $0.26 per kW, you spent over $98 so that's approx. 378 kw used in 640 miles, say you were only 85% efficient with charging and its still approx. 500 kWh/mi, seems like very high usage even for P3D+ fully loaded on the frwy. as a worst case scenario I have seen 280 kWh/mi on a road trip loaded down and in 45 degree weather which did draw another 10% over my usual.
Well, I'm getting the rated range+ (based on my projections) at a speed of 60-65 mph. I don't know what speed the EPA uses as "highway", but it seems to be working as advertised. I can definitely blow through the charge by going 75 mph and uses lots of HVAC. For example: Yesterday did a 130 mile round trip and got home with 78 miles on the "guess-o-meter". The starting "guess-o-meter" was 238....so 238 - 130 = 110 if you take 15%-20% off for heat and a cooling battery we're right at 78 miles left. It doesn't seem to be way out of line. My friend in Austin goes can go through almost half a charge almost in 60 miles because she's going 90-100 mph on the freeway there (the posted limit is 85 mph.) Speed is the key.
astrowunder
Member
Sorry if someone already posted this link- I don't have time to read 13 pages right now.
Tesla Range Table - Teslike.com
I find my P3D stealth with aeros gets very close to this chart. Under 65 without leadfoot I can get close to the rated range, which almost never happens for me.
Tesla Range Table - Teslike.com
I find my P3D stealth with aeros gets very close to this chart. Under 65 without leadfoot I can get close to the rated range, which almost never happens for me.
Maybe that's the round trip? 378000 watts over 640 miles is 590 watts per mile. Were you towing a trailer? lol
Glamisduner
Active Member
Overshooting then regen braking or regen braking when letting off throttle when it would be better to coast, reduces range. Obviously never braking is ideal and unrealistic. With the performance car it's easy to overshoot the speed limit and then let off the throttle. This is bad for efficiency. On my volt I would pop it into neutral when safe to do so on downhills and let the car speed up coasting. This is not easy to in the 3, so I aim for a throttle position that is close to neutral. But in general, on the performance 3 it's easy to accelerate to 60 then let off to get back down to the 50mph you meant to stop at, which is bad for efficiency. Depending on how you drive you might actually get more range with the lower regen setting. So it's a good thing to watch while driving. Regen and power usage is much more clean on the S/X than it is with the green bar in the 3.that's what I meant.. If I'm driving in the city I will need to brake at some point (red light, car in front of me, etc..) - that's why we have brakes, right?If I use regen braking in those situations and don't need my actual brakes, it's good for efficiency.
Not needing to brake at all (especially in the city) is unrealistic imo.
Which ICE car can do 0-60 in 3.3 seconds and get 24mpg
AlanSubie4Life
Efficiency Obsessed Member
Sorry! Hard to communicate in forums
. This is not anything deep I am saying here... I mean that friction braking is not something you should use instead of regen (obvious of course and you know this...but just clarifying what I meant by “except friction braking” - just meant you shouldn’t avoid regen if it means you have to use the brakes instead...obviously). Friction braking is always bad of course.By no friction I mean...obviously you have to use it to come to complete stop with Model 3 (more so with creep on I guess), but there is no significant energy to worry about when at very low speed (energy available to waste/reclaim is proportional to square of velocity) where you actually have to use the brakes. Not something to worry about. This braking really doesn’t matter.
Best to worst efficiency:
Best: No friction, no regen
Best, hilly: No friction, regen only on downhills to control speed. (Ideally you use as little regen as possible and use the speed you gain to coast out the bottom of the hill.)
Ok: No friction, regen wherever.
Bad: Friction and regen mix
Really bad: Rapid stops dominated by friction braking.
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JeffK
Well-Known Member
2019 Acura NSX and 2019 Mercedes AMG GT come close at around 22 mpg highway... both with higher horsepower than P3D.
Glamisduner
Active Member
JeffK
Well-Known Member
True, but you asked what ICE vehicles achieve those numbers so I Googled...
AlanSubie4Life
Efficiency Obsessed Member
Just two data points that might add to the conversation, with apologies if they've already been mentioned.
1. Aerodynamic drag is proportional to the square of the speed. So increasing speed by 10% (same as multiplying by 1.10) adds 21% (1.10x1.10=1.21) drag and energy consumption. If the EPA sets "rated range" (for example) with one person in the car at roughly 60mph and you're doing 75mph, then you're 25% above the EPA's numbers and will get 56% greater energy consumption (1.25x1.25=1.5625). Changes in speed create dramatic changes in energy consumption.
2. Climate control uses lots of power. In the 95F Florida summer, I average 380 Wh/mile in X100D. In the winter, with no climate control (winter is 75F), I regularly see 320 Wh/mile on highways, even 270 Wh/mile on city streets. My unscientific observation is that heavy climate control can increase your energy consumption by nearly 25%.
If you're driving faster than the EPA did to set the rated range, and you're using the A/C or heating a lot, you'll never get the rated range... but that would apply to any car, not just the EV.
1. Aerodynamic drag is proportional to the square of the speed. So increasing speed by 10% (same as multiplying by 1.10) adds 21% (1.10x1.10=1.21) drag and energy consumption. If the EPA sets "rated range" (for example) with one person in the car at roughly 60mph and you're doing 75mph, then you're 25% above the EPA's numbers and will get 56% greater energy consumption (1.25x1.25=1.5625). Changes in speed create dramatic changes in energy consumption.
2. Climate control uses lots of power. In the 95F Florida summer, I average 380 Wh/mile in X100D. In the winter, with no climate control (winter is 75F), I regularly see 320 Wh/mile on highways, even 270 Wh/mile on city streets. My unscientific observation is that heavy climate control can increase your energy consumption by nearly 25%.
If you're driving faster than the EPA did to set the rated range, and you're using the A/C or heating a lot, you'll never get the rated range... but that would apply to any car, not just the EV.
AlanSubie4Life
Efficiency Obsessed Member
Any of these comparisons should include information on the tires in use, not just the wheel diameter. The exact same tire compound and tread pattern is not used for these vehicle comparisons. As someone else noted, for *range*, at reasonably constant speed, wheel weight is probably not the dominant factor (and anyway, wheel weight is somewhat offset by reduced tire weight...)
@Dan_LA You are going to be extremely disappointed if you put PS4S tires on 18” wheels expecting a substantial range improvement!
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JeffK
Well-Known Member
Yes, this has been covered, it boils down to the opinion that Tesla should have rated the Performance model with the 20s (as that's the only way it comes now) to a more realistic range, not 310 miles.
It's a great number for LR RWD but a poor number for P3D.
Appreciate the link, wasn't aware of that. But yea I think 20" is the bad guy here, does that mean I need a lighter forged 20" wheel? Or it should be 18".
Yea wheel weight is playing a big role... 28lbs current weight... I saw some MONOs 23lbs.. just not sure wheel size. Appreciate your thoughts here, very very helpful. Just not sure 18" lighter wheel or 20" forged, the bigger wheel is just for looks or is there any benefit?
Glamisduner
Active Member
Smaller wheels with the same size tire will give a better ride quality for commuting, while larger wheels will reduce sidewall roll for performance and track usage.
opinion:
The 18's look too small, and 20's look best. I personally like the 19" option as they look better than 18's and are a nice in between. Light weight 19's would be nice.
AlanSubie4Life
Efficiency Obsessed Member
@Dan_LA, don’t worry about the weight! As far as efficiency goes, wheel size & weight is not going to make much difference, as several have pointed out. It just doesn’t matter much; boat anchors are (to first order) fine because a body that is in motion tends to stay in motion; the energy to maintain its speed is not strongly dependent on the weight. In fact, the heavier your wheels, the further you will coast! You should get 18” wheels, but that is just to increase your available selection of tires and to reduce your cost.
Obviously 2nd order effects - lighter is better. But it just won’t matter for this discussion. And the smaller your wheel the heavier your tire.
Obviously 2nd order effects - lighter is better. But it just won’t matter for this discussion. And the smaller your wheel the heavier your tire.
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