Range loss with and without mountain bikes/rack - ODBII logs - 2018 LEAF SL

[denwood]

I conducted a quick range test using our 2018 LEAF SL with two mountain bikes out back on a 1uP Super Duty rack. 2" reciever is from Ecohitch. Data logged using LeafSpy Pro. Calm winds, flat section of highway driven in both directions, no drafting etc. Speed was set at 100km/h using the car's cruise. Range loss predicted on watts actually used would be 21-26%. Average loss using all data was 23%.

 

[denwood]

I ran another quick test after swapping over from the winter rims/tires, to the summers.

The studded winters (most studs are worn to tread depth) I’m using on the car are actually about 4% more efficient vs the wider/lower profile Ecopia EP422 Plus summers. At 97 kmh, the winter tires/rims (205/55/R16) averaged 11 774 watts in my test and Ecopias (215/50/R17) were 12 226 watts, 4% more.

 

[DougWantsALeaf]

4% is 8-9 miles of freeway range. But some of that efficiency is also reduction in unsprung weight. Stock 16" rims are 4lbs less than 17" stock rims each. The tires are also each 1.5lbs less each..

 

[Bombastinator2]

Racks of any kind play hob with aero. I had some roof racks on an old 2003 mini but they were so loud I had to take em off.

 

[denwood]

Racks of any kind play hob with aero. I had some roof racks on an old 2003 mini but they were so loud I had to take em off.

One thing I will say with the hitch mounted rack..I don't notice much for increased noise (windows closed) on the highway at 100km/h with bikes mounted.

 

[denwood]

4% is 8-9 miles of freeway range. But some of that efficiency is also reduction in unsprung weight. Stock 16" rims are 4lbs less than 17" stock rims each. The tires are also each 1.5lbs less each..

Good point, however I tested only steady state, flat highway, no acceleration. The difference is likely due to rolling resistance, at least the majority of it. 195/16/55R vs 225/50/R17 is quite a difference.

 

[Bombastinator2]

One thing I will say with the hitch mounted rack..I don't notice much for increased noise (windows closed) on the highway at 100km/h with bikes mounted.

It makes sense that it would have less drag than a roof mounted one. I wonder what would. Happen if yo did some simple aero like putting a cloth cover over them. Would fully obscure the rear view mirror but you’ve still got the backup camera and the side mirrors. Would also keep damp off the seats.

 

[denwood]

Covering the bikes would almost certainly make efficiency worse as the frame and wheels etc. are quite “permeable” with regard to air flow.

 

[johnlocke]

Covering the bikes would almost certainly make efficiency worse as the frame and wheels etc. are quite “permeable” with regard to air flow.

Actually it might help. All those spokes and tubes cause a lot of turbulence and induced drag. The improved airflow might offset the increased frontal area. Reduction in turbulence at the rear of the car can make a big difference. You should at least try it.

 

[denwood]

Actually it might help. All those spokes and tubes cause a lot of turbulence and induced drag. The improved airflow might offset the increased frontal area. Reduction in turbulence at the rear of the car can make a big difference. You should at least try it.

I'd agree that testing this out is would be worth it. Not sure it would take much off the 25% hit I've measured already, but with an EV (at least one with the LEAF's range) even 4-5 percent is significant.

I'd bet a beer or two that a solid cover would work better than a flexible one, certainly easier on the bike with respect to abrasions, flapping etc.

 

[Bombastinator2]

Covering the bikes would almost certainly make efficiency worse as the frame and wheels etc. are quite “permeable” with regard to air flow.

I
The cover would likely have to be connected to the hatch. A longer car with a somewhat lumpy back as far as air is concerned. It may be permeable but there are all those spokes and things. You may wind up being right though.