Hypermiling techniques?

[joeytree]

Thanks for your input @WannabeOwner ! I'm also unsure about rate of charge on the S60D since I don't completely understand how it charges with the software limitation. In this instance, I'm wondering if a full charge would be 30 minutes or less, since my Tesla rep confirmed that the car is software limited in terms of charging to only 60 kWh out of the full 75 kWh (i.e., 80%) of the battery pack (as opposed to being discharge-limited). I'll ad that to the list of questions I'm making for my Tesla rep for when she's back from vacation next week.

 

[WannabeOwner]

You've probably seen it, but some S60 charging-rate data here (but charging was shared with another vehicle, so not best-possible)

Some exciting observations about the new Model S60 (software limited 75 kWh)

 

[joeytree]

Thanks again @WannabeOwner, I hadn't seen that thread. In case anyone is interested, I received different information than @privater from by Tesla delivery specialist yesterday about fully charging the S60. The short of it is that my delivery specialist said the S60 should still only be charged to 80-90% on a regular basis. See my post on page 2 of the discussion for a more detailed explanation:

Some exciting observations about the new Model S60 (software limited 75 kWh)

The information from my delivery specialist also means that fully charging an S60 should be slower than charging an S75 to 80%, though I would still expect it to be faster to charge an S60 to 80% than to charge an S75 to 80%.

 

[scottm]

Nobody brought this up yet: fold the mirrors in on the hiway. Reduces the frontal surface area, lower drag.

 

[Buddy]

Nobody brought this up yet: fold the mirrors in on the hiway. Reduces the frontal surface area, lower drag.

I see why this would work but without testing it in a wind tunnel or something like that it is speculation.

 

[jerry33]

Nobody brought this up yet: fold the mirrors in on the hiway. Reduces the frontal surface area, lower drag.

Maybe. However, if you fold them in:

1. They stick out almost as far so you're not reducing the frontal area by much.
2. The front area of the mirror will be flat rather than aerodynamic.

I'm not convinced that folding the mirrors will improve things--it might even hurt. Without real testing, it's difficult to say.

 

[scottm]

They're still aerodynamically shaped when folded, take a look!

Better yet take the mirrors off completely... they're a known bane to windflow and EV needed efficiencies.

Elon wants to get rid of them for two cameras instead.

Even Mercedes was on to this, for my 1987 300D the passenger exterior mirror is notably smaller than the driver side. They bragged about low drag for that car in the marketing material and pointed out all the things they did to improve it, including shrinking that mirror for w124 chassis Eclass.

 

[stevezzzz]

That may actually be the best policy - unless your Mom wants to avoid stopping altogether.

Best range is at 25 MPH ... of course it takes you ALL day to get there! Drive at 100 MPH and increased air resistance means you use far more fuel, so have to stop more,and overall it takes you longer.

I believe the sweet-spot is somewhere around 70-75 MPH. You will have to stop, but the time-to-charge, at that average speed, is the same as the driving time - whereas extra time to charge with average speed of 100 MPH is longer than the driving time, and at 25 MPH time-to-charge is much quicker than the driving time. It does depend on arriving at chargers "close to empty", because the battery charges faster when empty, compared to nearly full, and it may be different for S60 than S90, because the bigger batteries add more range, per unit of charging-time.

Starting at 100% SoC and arrive at destination at close to 0% will also help - so on the final leg, once you know you have enough "fuel" to reach your destination (line on the Trip Graph is all green), you can speed up. Just be prepared to slow down if the trip graph starts to show yellow (you will need to show your Mom how to program the supercharger stops into the SatNav, and how to use the Trip Display)

The optimal cruising speed (defined as the cruising speed that gives the highest average speed-made-good toward the destination, including charging stops) depends entirely on the rate of charge you can expect at the next charging stop. The faster your charge rate, the higher your optimal cruise speed. If you make a time plot of the SOC, the optimal cross-country speed made good produces a perfect sawtooth pattern: the discharge rate during cruise is the same as the charging rate, and you spend exactly 50% of your time charging and 50% driving. Optimally, you should also arrive at your final destination with 0% SOC, or as close as you can manage it: it's far better to arrive at 5% SOC than fall short by a mile or two.

As a practical matter when using only Superchargers, you can't legally drive fast enough to achieve a discharge rate equal to the average charge rate, even if you charge well into the taper. The good news is that driving slower than optimal exacts much less of a penalty than driving faster than optimal. Besides, the calculations are thrown off by the time and distance overhead of leaving the highway to access a charger; better to drive a few mph slower and be able to skip a charger entirely, so long as you don't run out before the next.

 

[joeytree]

I've had my S60D for about a week now. I"m still getting used to getting good efficiency when local driving (I only get to use it on weekends since I take the train to work), but I think I found a driving method that greatly improves efficiency at least on the highway. In particular, I've noticed that Autopilot does a pretty efficient gob of driving by itself, averaging around 250 Wh/mi or less on the couple of 100+ mile highway trips we've taken. But one deficiency is that it won't coast when going downhill. But the adaptive cruise control will remain engaged even if you depress the accelerator. So you can manually make the car coast going downhill and just keep your foot in position until the cruise control takes over again. Better yet is to keep your foot in that position for most of the ride so that you don't end up regenerating much downhill before you catch it an initiate coasting. In mixed driving, this brought me down from around 300 Wh/mi to under 208 Wh/mi at times (for the most recent 30 miles of the trip). In the end, our 60+ mile mixed trip was around 250 Wh/mi, whereas the first half of the trip (before I started using the above technique) left me thinking I'd be lucky to get home under 300 Wh/mi.

Regarding local driving, The biggest problem I'm having is going up and down hills. It seems that the car accelerates faster when coasting downhill than our LEAF, so I have to engage regenerative braking sooner then typical. I've had no trouble getting around 250 Wh/mi for highway trips, but I always seem to get around 300 Wh/mi when just local driving. Ironically, I have no trouble in the LEAF increasing my local efficiency to under 200 Wh/mi (over 5.0 mi/kWh) compared to my average of ~215 Wh/mi (between 4.6 and 4.7 mi/kWh). While I expected the numbers themselves to increase due to the increased weight of the car, I expected to see a similar trend (i.e., better local efficiency than highway). Is this difficulty typical, or does anyone have tips on improving efficiency when driving locally?

 

[hiroshiy]

I've had my S60D for about a week now. I"m still getting used to getting good efficiency when local driving (I only get to use it on weekends since I take the train to work), but I think I found a driving method that greatly improves efficiency at least on the highway. In particular, I've noticed that Autopilot does a pretty efficient gob of driving by itself, averaging around 250 Wh/mi or less on the couple of 100+ mile highway trips we've taken. But one deficiency is that it won't coast when going downhill. But the adaptive cruise control will remain engaged even if you depress the accelerator. So you can manually make the car coast going downhill and just keep your foot in position until the cruise control takes over again. Better yet is to keep your foot in that position for most of the ride so that you don't end up regenerating much downhill before you catch it an initiate coasting. In mixed driving, this brought me down from around 300 Wh/mi to under 208 Wh/mi at times (for the most recent 30 miles of the trip). In the end, our 60+ mile mixed trip was around 250 Wh/mi, whereas the first half of the trip (before I started using the above technique) left me thinking I'd be lucky to get home under 300 Wh/mi.

Regarding local driving, The biggest problem I'm having is going up and down hills. It seems that the car accelerates faster when coasting downhill than our LEAF, so I have to engage regenerative braking sooner then typical. I've had no trouble getting around 250 Wh/mi for highway trips, but I always seem to get around 300 Wh/mi when just local driving. Ironically, I have no trouble in the LEAF increasing my local efficiency to under 200 Wh/mi (over 5.0 mi/kWh) compared to my average of ~215 Wh/mi (between 4.6 and 4.7 mi/kWh). While I expected the numbers themselves to increase due to the increased weight of the car, I expected to see a similar trend (i.e., better local efficiency than highway). Is this difficulty typical, or does anyone have tips on improving efficiency when driving locally?

Not a quantifiable way of explaining, but generally if the car is heavier local efficiency is reduced because it needs to recover energy via regen and it's like 50% efficient. If the speed is higher, the car uses much less regen and instead lose more to aerodynamic loss.

Leaf is a ligher car with less aerodynamic body, so it will better perform in local driving but worse in highway.
Tesla is a heavier car with slippery body, so it will perform worse in local driving but better in highway.

Hope this helps. Actually if you compare latest 2016 90D and 2016 Leaf, Tesla is more efficient than Leaf on highway (better mileage)!