AlanSubie4Life
Efficiency Obsessed Member
This seems like a terrible idea vs. careful accelerator pedal modulation, but have you tried: “Push the lever up or down to the first position and hold it there for more than 1 second to shift into Neutral”?
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Disappointing Range in P3D. Is this normal?
- Thread starter AtlasReardan
- Start date
This seems like a terrible idea vs. careful accelerator pedal modulation, but have you tried: “Push the lever up or down to the first position and hold it there for more than 1 second to shift into Neutral”?
AlanSubie4Life
Efficiency Obsessed Member
Extremely unlikely to be beneficial on a road trip unless you cannot modulate the accelerator.
At freeway speeds it is actually extremely easy to avoid entering regen.
And even if you occasionally do enter regen slightly, it is unlikely to help, net, on a trip, to stop that from happening, because the user of such a mode then would have to use the brakes in many situations.
Regen can always be prevented entirely with accelerator pedal application.
AlanSubie4Life
Efficiency Obsessed Member
Extremely unlikely to be beneficial on a road trip unless you cannot modulate the accelerator.
At freeway speeds it is actually extremely easy to avoid entering regen.
And even if you occasionally do enter regen slightly, it is unlikely to help, net, on a trip, to stop that from happening, because the user of such a mode then would have to use the brakes in many situations.
Regen can always be prevented entirely with accelerator pedal application.
MasterC17
Active Member
Some more data. Purchased a P3D+ for my wife in June. Retrofitted to Base brakes, installed Stock 18" Aero Wheels/Tires, installed UP Front Lip, retained stock P3D+ spoiler. Pressures set to 48psi.
Drive (to and from) from yesterday:
Drive 1: 39.046 Miles
Avg Speed: 73.22mph, Max 83
Wh/Mi: 238
Ambient: 90f
2.5mph Wind (blowing South, traveling East)
Drive 2: 39.387 Miles
Avg Speed: 75.84mph, Max 80
Wh/Mi: 243
Ambient: 80f
5mph (Head)Wind (blowing East, traveling West)
This was with the Aero covers off. I still need to install the UP Rear Spoiler once it arrives (September), retrofit S Calipers on the front with lightweight 2-pc rotors (saves about 4 pounds on each corner), and finally MPP Comfort Coilovers have shipped but not arrived.
Based on my calculations, just adding the front lip makes the car about 6% more efficient at 75mph (which is basically what UP claims).
UP claims another 8% from lowering roughly 1.5 inches, and an additional 4% with the rear spoiler (over the stock one).
We're taking a 700-mile road-trip next weekend, and I am going to tape all the edges with some 3M vinyl tape. Maybe get a percent or two! Unfortunate I couldn't get the coilovers or spoiler installed before the trip, but makes for a good comparison later.
Drive (to and from) from yesterday:
Drive 1: 39.046 Miles
Avg Speed: 73.22mph, Max 83
Wh/Mi: 238
Ambient: 90f
2.5mph Wind (blowing South, traveling East)
Drive 2: 39.387 Miles
Avg Speed: 75.84mph, Max 80
Wh/Mi: 243
Ambient: 80f
5mph (Head)Wind (blowing East, traveling West)
This was with the Aero covers off. I still need to install the UP Rear Spoiler once it arrives (September), retrofit S Calipers on the front with lightweight 2-pc rotors (saves about 4 pounds on each corner), and finally MPP Comfort Coilovers have shipped but not arrived.
Based on my calculations, just adding the front lip makes the car about 6% more efficient at 75mph (which is basically what UP claims).
UP claims another 8% from lowering roughly 1.5 inches, and an additional 4% with the rear spoiler (over the stock one).
We're taking a 700-mile road-trip next weekend, and I am going to tape all the edges with some 3M vinyl tape. Maybe get a percent or two! Unfortunate I couldn't get the coilovers or spoiler installed before the trip, but makes for a good comparison later.
I find the P3D upgraded brakes to have more brake drag than the base brake system. My rear rotor is always hot even if I didn't use much mechanical brakes.
My steady state 250 Wh/mi is around 76mph with AC set to 71 on 80f ambient. Car is lowered 1.2 inches without any aeroes. Stock 18 inch with aero cap in the front and 18 inch aftermarket wheel in the rear with stock 18 tires.
However, I find my battery capacity to be much smaller than spec base on my road trip stats. Not sure what everyone else is seeing
My steady state 250 Wh/mi is around 76mph with AC set to 71 on 80f ambient. Car is lowered 1.2 inches without any aeroes. Stock 18 inch with aero cap in the front and 18 inch aftermarket wheel in the rear with stock 18 tires.
However, I find my battery capacity to be much smaller than spec base on my road trip stats. Not sure what everyone else is seeing
MasterC17
Active Member
I think that the 77.5 kWh is the true capacity, "usable" is less (like 72.5). Assume roughly 5% degradation in the first year, puts you right at ~69kWh with a few kWh of "reserve" after Rated Range is 0.
FWIW, you can use the base rear calipers with the performance rotors. That's the setup I am running of my wife's. Sheds a few pounds, allows for stock 18" aero wheel, and the pads aren't much smaller.
AlanSubie4Life
Efficiency Obsessed Member
Every time I measure, I get ~230Wh (displayed) /rmi. (rmi = rated mile). However, the discrepancy is likely due to the meter reading displayed in the car (I do believe the battery has about 77.5kWh available, so your constant is correct - but it won't match calculations done using what is displayed in the car).
Your calculated results seem to differ from my constant (though they should not). The amount of error depends on how carefully you measured the data, and your battery pack health.
1) If you literally spent zero time in park for each of the above data points, this should be good data. However, if you weren't very careful to record the data at just the right time, account for rounding error, etc., that can introduce some error, especially when using % rather than rmi.
2) Also, your % numbers make it hard to tell what your pack would give you in rated miles at 100%. (I've assumed 310rmi below - but if your battery were "degraded" to say, 300 mi at 100% charge, the numbers would match my 230Wh/rmi constant. My guess is that at 100% your battery does not currently give you 310 mi - maybe closer to 300 miles.)
Your results suggest your constant is about 220Wh/rmi (but again - this is not the way to calculate the constant - when using %, you must include the projected full pack capacity in rated miles in the formula below to calculate this constant correctly - or use delta in rated miles, rather than delta %):
283Wh/mi*208.3mi/((0.99-0.13)*310rmi) = 221Wh/rmi
289Wh/mi*141.9mi/((0.97-0.38)*310rmi) = 224Wh/rmi
260Wh/mi*194.4mi/((0.92-0.18)*310rmi) = 220Wh/rmi
For a brand new battery, the observed constant implies available energy (per the meter) as 310rmi * 230Wh/rmi = "71.3kWh." I use quotes because these are "meter kWh."
So it would make sense that if you find that "69kWh" are available that your full charge would be about 300rmi.
We know for sure of course a brand-new battery contains more energy than that (about 78kWh, based on EPA submissions). The explanation is that the battery pack has a little unused margin below 0 miles, and also, note that the meter in the car is just a meter. It really does not have to be accurate or accurately state the consumption - and there's plenty of evidence that it doesn't (see the EPA submissions - there is definitely closer to 77-78kWh available if you run the battery all the way to dead - and the current clamp meters used for that test would need to be accurate to comply with government rules.)
My guess is the meter reads a few % low (5%?) and the rest is explained by the reserve capacity. For you, either you have some degradation ("71.3kWh" to "69kWh" - I doubt you actually have 3% degradation though) or the BMS is not letting you charge up all the way to the level the EPA test originally used, right now.
So after calibrating your in-car meter error , you have about 73.5kWh of battery capacity available right now, when discharging all the way to 0 miles (and perhaps 75kWh available if you drive until the car stops moving).
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Been a while since I checked in here, and coming up on a year since my original post. As you can see, it's continued to settle slightly. At 14,734 total miles driven, the average has come down to 324 Wh/mi. The range issue is certainly still an annoyance in an otherwise good car. But since my usage usually doesn't require me to exceed the limitation in a single day, I can usually put it out of my head. So for me at least, it's just road trips or extra-long weekend jaunts that become more cumbersome than they were in my ICE vehicle.
For reference when looking at the stats below, I try to keep my tires at 42 psi (cold). I rarely use my friction brakes, but I'm not so religious about trying to avoid my regen brakes (and keep the bar in the center when I'm not accelerating).
For reference when looking at the stats below, I try to keep my tires at 42 psi (cold). I rarely use my friction brakes, but I'm not so religious about trying to avoid my regen brakes (and keep the bar in the center when I'm not accelerating).
AlanSubie4Life
Efficiency Obsessed Member
Looks good! On target for 220 miles on a full charge. Excellent. Plenty of range for road trips.
For "science," you should reset your other trip meter once you get the latest updates. Eventually it's possible you'll get an update soon that improves efficiency. After another 14k miles (over a similar time interval), you can compare and see whether you see 3-4% better (that's supposedly what we'll get, they allegedly have eked out some efficiency improvements, but it's very unclear if it only will apply to 2020 hardware). So maybe you'll get as low as 310Wh/mi!
Lots of variables though (tires/wear level, weather, type of driving, etc.), so to be honest it's going to be really hard to discern a 4% difference even over a very long interval.
AlanSubie4Life
Efficiency Obsessed Member
And better efficiency than prior years, apples to apples! I'm really hoping those improvements come to the 2018s too. We'll see. The P3D Stealth is actually the most efficient AWD vehicle that Tesla sells now (probably 326 rated miles or so, even though it says 322 in this chart)! As long as you have the 18".
The Performance Stealth was 116MPGe in 2018, now it is 124MPGe! That's huge! And it has at least 50 more HP than it had back then... Wonder what all the reasons are for the improvement...
I'm really glad Tesla is now calling out the vehicles by wheel size. Hopefully there will be fewer questions about why the range is poor with the 20", but I doubt it.
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More granularity is always a good thing, but yes i suspect you're right. People with a lead foot will always come here asking why they aren't getting 300 miles per charge
Jedi2155
Model 3 has Arrived.
Camera-Cruiser
Fully Charged
I’m at 275 Wh/mi average over the last 15K miles on my P3D+ on stock 20” wheels. Like @Jedi2155, I’ll average in the 260ish Wh/mi range commuting in LA OC traffic. Today, being a holiday in the US, meant lighter traffic and higher speeds (70-80mph) so I averaged 278 Wh/mi covering 85 or so miles.
Key to efficiency is use the acceleration judiciously and drive modestly the rest of the time. Even then you’ll still pull away from everything else at most lights.
Key to efficiency is use the acceleration judiciously and drive modestly the rest of the time. Even then you’ll still pull away from everything else at most lights.
The other way to fix the problem would be to just have a bigger battery. If it had a 100kw battery, then it would be a perfect amount of range at my 324 Wh/mi. My last car was a 911, and it easily got over 300 miles on the highway on a tank of gas regardless of how I drove it. Although, in the last year, I've lost about 15 miles of "range" from where it used to be at a 90% charge. So I'm kind of concerned that this could get to be a bigger problem as the battery ages.
Guess I need to start saving for a Roadster, or maybe one of those new "Plaid" Model S' in 2020 (although, I prefer the smaller size of the Performance Model 3)...
Guess I need to start saving for a Roadster, or maybe one of those new "Plaid" Model S' in 2020 (although, I prefer the smaller size of the Performance Model 3)...
AlanSubie4Life
Efficiency Obsessed Member
To be honest, for SoCal, your numbers seem a bit high, unless you 1) spend a lot of time traveling at 90mph 2) like you use your brakes, or 3) are not using the stock 20” tires. Or, possibly, you love to blast the AC and heat whenever possible.
Your tires are wearing evenly, not excessively? Just wondering about excess toe for you. But you would probably know it by now - because you would have had to replace tires.
I do a lot of surface street driving, but I do have quite a lot of hills to deal with (which is bad even if I don’t use the brakes), and I still end up around 280-290Wh/mi even with a lot of AC use. If I did more level freeway driving, I’d expect more like 300Wh/mi.
I would say "plenty of range for daily use," but definitely not for road trips. Is it manageable? Yes, it is (especially since we have a lot of Superchargers in California). And I'm willing to manage it since I enjoy other aspects of the car, and road trips are a low'ish percentage of my usage.
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