Unexpected Conserve vs All Purpose Efficiency Behavior

[Budman]

I've posted this data a few time on this forum. I am continuing to collect data but an odd pattern is showing up.

I do a frequent 165 mile trip between my home near Minneapolis to my cabin near Hayward, WI. Been doing it for about 1.5 years now in my R1T. Most of the first year was in conserve mode and I saw very consistent and predictable behavior with temperature. Most of this summer and fall has been in All Purpose, with a few conserve trips in the mix. The all purpose efficiency is inconsistent with not much of a change with temperatures being seen so far. I've have also done the trip many times with a bike rack on the hitch or a bed top tent, those have all been in conserve and that data seems to make sense. I even did one recent trip in conserve with the tonneau open (Gold X on the chart) with some articles in the bed and that was smack dead on the other conserve data.

I will continue to get data but wanted to share what I've seen so far. I don't have any real good explanation...... Same set of tires for all trips and I don't think it is a time based issue or tire tread wear issue because I've mixed in some conserve trips with the all purpose trips this summer and the conserve data fell right in line with past observations.

R1T with 21" road tires with PSI always between 45 and 50 psi.
In Conserve ride height is "low".
In All Purpose ride height is "standard".
If it happens that there is a head or tailwind of greater than 15 mph I do not include that trip in the data set.

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[Redline]

How has your tire wear been so far?

 

[Budman]

How has your tire wear been so far?

At 31,000 miles. Still about 2 mm above the wear bar. Will replace soon before winter really hits around here. Rotated twice. At 10k and again at 20k.

 

[Redline]

I haven't done my first road trip to the cabin yet, but will next weekend. I've stayed in AP nearly all the time so far...I'm a bit worried about tear wear with conserve, but it seems you're having good luck with it.

 

[Budman]

I haven't done my first road trip to the cabin yet, but will next weekend. I've stayed in AP nearly all the time so far...I'm a bit worried about tear wear with conserve, but it seems you're having good luck with it.

I've done ~10,000 miles in conserve with no issues.

 

[Riviot]

Tldr; conserve/low does better than All Purpose /standard? That's... Predictable. You only have Conserve data for rack or tent, so you can't compare anything about it with All Purpose.

 

[Budman]

Tldr; conserve/low does better than All Purpose /standard? That's... Predictable. You only have Conserve data for rack or tent, so you can't compare anything about it with All Purpose.

You missed my point, perhaps I wasn't clear. My point is the All Purpose (Black Data) is relatively unchanging with temperature and generally inconsistent vs the consistent and repeatable temperature trend with Conserve (Green). Truck is configured the same black vs green.

 

[Riviot]

You missed my point, perhaps I wasn't clear. My point is the All Purpose (Black Data) is relatively unchanging with temperature and generally inconsistent vs the consistent and repeatable temperature trend with Conserve (Green). Truck is configured the same black vs green.

I see.

Your wind threshold is 15mph, which is really high. Anything over 5 will really make big impacts. All purpose/standard is a bigger sail than low. Perhaps use all purpose with standard instead to remove a variable?

 

[Budman]

You missed my point, perhaps I wasn't clear. My point is the All Purpose (Black Data) is relatively unchanging with temperature and generally inconsistent vs the consistent and repeatable temperature trend with Conserve (Green). Truck is configured the same black vs green.

Perhaps this graph better illustrates the point.

 

[obababoy]

I haven't done my first road trip to the cabin yet, but will next weekend. I've stayed in AP nearly all the time so far...I'm a bit worried about tear wear with conserve, but it seems you're having good luck with it.

I think some of the big tire wear issues in conserve come down to smoothness. If you are going to hop on steady roads and have minimal regenerative braking, you will have quite a bit less wear up front.

 

[Budman]

I see.

Your wind threshold is 15mph, which is really high. Anything over 5 will really make big impacts. All purpose/standard is a bigger sail than low. Perhaps use all purpose with standard instead to remove a variable?

Ride height was about the only explanation I could come up with. But if that is what is behind this, it is a much bigger factor than I would have expected.

 

[Riviot]

Ride height was about the only explanation I could come up with. But if that is what is behind this, it is a much bigger factor than I would have expected.

Oh for sure, it's a huge factor. It changes aero dramatically which has exponential impacts with speed changes. Even when we need snow or all purpose on our road trips, we stick to low and stiff over 50mph.

 

[zefram47]

Perhaps this graph better illustrates the point.

I don't have anywhere near enough data yet, but running ElectraFi for the past month across a wide swath of temperatures on my commute I also see pretty flat efficiency in AP Standard. I'm not seeing the efficiency really fall off until the temp is below freezing.

 

[zefram47]

Oh for sure, it's a huge factor. It changes aero dramatically which has exponential impacts with speed changes. Even when we need snow or all purpose on our road trips, we stick to low and stiff over 50mph.

This is in stark contrast to the testing that OoS Kyle did early on. He found that ride height had almost no impact to efficiency running identical loop-style tests in more or less identical conditions.

 

[Riviot]

This is in stark contrast to the testing that OoS Kyle did early on. He found that ride height had almost no impact to efficiency running identical loop-style tests in more or less identical conditions.

I don't watch all their stuff, though I do find it informative. Can you link it? How long was the loop and what were the speeds?

It'll be hard to get multiple tests done with consistent conditions, but I'll give it a shot over the next couple weeks.

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