LT Tire Choices

[zipzag]

Consumer Reports once took a Golf and did nothing but vary the rim diameter, keeping overall wheel radius the same. They found range dropped 10%. It's a bit hard to determine whether it was the weight or the rolling resistance, though.

Should not matter at a steady speed. Accelerating the mass is what is costly, although I expect the 4x penalty quoted above is without energy recovery/regen.

Sponsored

 

[zipzag]

Likely this is why Rivian ended up with the 21" wheels & tires..... It's such a weird and goofy choice. Unfortunately it hangs anyone who has them with virtually no other tire choices now and in the future.

I'm sure Tesla will do something similar with Cybertruck. There's the right tire for a fancy offroad centric truck. Then there is the other tire that gives the best EPA number and highway range.

 

[Riviot]

I'm disappointed in your brand choice (wink wink) but interested to hear how they perform. I've got my swap planned for this weekend and will share thoughts as well.

Did you swap yet? Can you post about it, with pics, info, stats, etc in a new post? I'm eyeing your previous choices.

 

[mmiles2012]

Did you swap yet? Can you post about it, with pics, info, stats, etc in a new post? I'm eyeing your previous choices.

I had planned the swap for yesterday, but the folks at the store didn't order my tires before the Saturday delivery cutoff from the DC. When I get them, I'll absolutely post some pics and impressions.

The ironic part of this is that I called ahead to make sure they had them on hand or ordered for Saturday, since I worked on the project that set up our retail DC network......

 

[mmiles2012]

Did you swap yet? Can you post about it, with pics, info, stats, etc in a new post? I'm eyeing your previous choices.

Update: these are going on today but then I'm going out of town for the rest of the week. I'll get some photos and initial thoughts this weekend.

 

[mmiles2012]

It's not a matter of perspective. Its physics.

The moment of inertia for heavier tires, if the weight is concentrated towards the treads rather than the sidewalls, will definitely affect the range due to higher energy required to rotate them. Think of figure skater's spinning rate with his/her arms out versus tucked in. The energy required for the skater to rotate is the same.

It is also more than compound too.

Last, ANY new tires will have higher rolling resistance than the same tire as it wears down. Why? Because less mass at the treads.

I’ll have to caveat a lot of this, because my inner former engineer keeps saying “remember Mike, you are not a tire engineer.” So, I’m not an engineer (anymore), let alone a tire engineer, although I do work for a tire company.

Having now said that, I don’t know that I buy MOI = rolling resistance. Or even that they are correlated. Example: BMW i3 tires (some wacky 175/55r20 there - so quit yer yappin, 21” wheel owners!) - which, as a thin narrow hoop, are the worst case for MOI of a tire- all the weight way far away from the axis of rotation. Yet these were developed as EXTREMELY LRR tires- which is why they’re so skinny in addition to special compound. Rolling resistance is the force the road applies back to the tire that’s equivalent to friction. Contact patch size and shape plays a huge factor here - but I don’t think MOI does.

I certainly could be wrong though - as I’m not a tire engineer, etc.

 

[Mark_AZR1T]

I've made numerous posts on my Cooper AT3 XLT Discoverer tires. 8,000 miles. Ride excellent, sound as quiet as Pirellis (close), wear excellent and because they are load range E, the operational pressure range is up to 80psi. I run them at 60+ for 5000 miles and range loss is not measurable.

8,000 mile wear below. Easy 30-35K I believe on these.

Sponsored