NeilBlanchard wrote:Using wider / heavier tires will lower range, and open wheels adds more aero drag, which is also harmful to range.
Narrower and lower rolling resistance tires increases range, and smooth flat wheels also help increase range.
Look at the BMW i3 for the best wheels and tires for increasing range. And all else being equal, larger diameter wheel will have lower rolling resistance.
I'm totally new (5 days!) to the Leaf world, enjoying late evening reading threads here.
Am I missing something, or is this ^^^ the first post in this thread that addresses tire width? Has no one tried going to a NARROWER tire on the stock rims, i.e. 195-55 x 16"? Aren't Leaf owners interested more in range than visual aesthetic?
I doubt there would be significant loss of traction/handling, but the smaller surface contact might have an impact on effect on range.
Just my two-cents...and my very first post here!
With tires there are lots of trade offs.
A few of the important things to think of when you buy tires for range are width (wider will be less aero), rolling resistance, max PSI (if you're willing to go over 44 as many have), weight and over all diameter. The biggest problem with 195 55 16 is that the diameter is small. the stock 16s are 24.9", stock 17s are 25.5. The diameter will change the over all gearing of the car, as well as the speedo and the ODO. If you are leasing your car and going over millage then you definitely don't want to change the ODO to put more miles on the car as you'll have to pay later for that. Gearing probably isn't as much an issue on electric cars for efficiency as they are on an ICE but with all things being equal a wheel that is larger will have less rolling resistance than a wheel that is smaller. I used the term "wheel" there because you can't compare 2 tires of different sizes as apples to apples because so many things change when they are making them. Even tires made with the same brand and model in 2 different sizes can be made very differently even if the tire looks identical. You can see this if you shop for tires on a UK website. They have to list the rolling resistance as a letter grade, ie A B C etc... and within the same tire model you have wide swings in rolling resistance. Sometimes even in the same model same size but say 1 is a BMW fitment 1 is audi and you'll see different rolling resistance. For people who do a lot of highway driving rolling resistance and aero matter the most.
For city driving with lots of stop and go the lighter weight of a smaller 195 55 16 may be a benefit, as well the change in gearing will make the car feel faster off the line. If putting extra miles on the ODO isn't an issue and someone wanted to try that for gearing change I'd actually recommend trying it with a 185 65 15, 24.5" and 17lbs on light weight 15s which you can easily get in the 10-12lb range. Finding ones that fit is a pain though. I thought about that for my winter wheels but since I do mostly highway and it's a lease I went with the 205 65 15 (25.5" and 20lbs).
If you were to stick with 16s and wanted to go narrow the best size to try would probably be the 195 60 16 (25.2"). However tires in that size are slim picking. There's the Michelin Xice which is a great winter tire, and can be driven in the summer too if it's not too hot and you don't drive hard as well as the Yoko Avid Ascend but Yoko tires are heavy (this one is 21lbs vs 19 for the Xice).
The i3 that was mentioned above has really big tires when you look at the diameter, the contact patch of a narrow and large diameter tire is also much larger, 27.5" or so which is a trade off by going narrow. I really wish that more auto makers were embracing that change. I first heard about the Bridgestone concept years ago and I'm not sure if it came as a result of the i3 or if that's what BMW choose because Bridgestone had worked on it. However it is such a change in the design of a car that they would have to pick that tire size before they started most of the development of the car.
gncndad wrote:....Am I missing something, or is this ^^^ the first post in this thread that addresses tire width? Has no one tried going to a NARROWER tire on the stock rims...
This has been discussed, but AFAIK, no one has actually done it and posted results.
Remember, many of those most obsessed with range are referring to range at freeway speeds
, where tire/wheel selection will produce limited benefits.
I do most of my driving at lower speeds on rural roads, conditions where tire selection can make a large difference in range. I expect the available capacity from my OE pack to fall below 17 kWh before I need to replace my second set of tires, at about 60 k miles in late 2017.
At that time, range from my home charge might become a significant limitation to my driving, so I may consider the skinny tire
From my experience tire selection has a huge benefit to freeway speeds but mostly by going with the lowest resistance tire you can and going with the highest PSI available. Another factor is those that do a lot of highway driving of 60 miles plus a day will also want a tire that will last a long since they will be putting more miles on the car.