Energy Efficient Tyres

dolj · Oct 20, 2014

*Goldfinger* said: ↑

Waterhouse said: ↑

Needed new tires for my 2010 Prius III (63K mi). OEM's were Yoko Ascend's, pumped to max press 44 psi. Was averaging 64 MPG (dashboard) on my daily commute.

Tried to find Mich. Energy Saver A/S's, but availability very limited. The tire guy tried to talk me into Defenders or Premier A/S's.

On the Michelin site the ES A/S is rated with a fuel efficiency of 10 (best), Defender: 8, Premier A/S: 9. Well he got me with the Premiers with their tread ware rating of 640 (over 480 for the ES A/S's, and hey 9 is not much less than 10, right?).

I'm now seeing a drop in my daily commute MPG of over 8% (again as max press 44). I can attribute only about 3% to greater tire diameter with full tread. I'm taking Michelin up on their 30-day promise and holding out for the ES A/S's. We'll see what's the difference between Michelin's 9 and 10 rating for Fuel Efficiency.

Edited 9/11/14: The saga continues - I called the tire guy said I wanted Energy Saver A/S's. He said OK, he'd look for availability - they're really hard to find. He called me back the next day and surprise - he had them. Cool - I go to get them installed. Job done, I go out to my car and they've put on Energy Savers - NOT A/S's! He gave me Mich part #14710 instead of #41536. They're more expensive and tread warranty is 50K instead of 65K. I grumble, he gumbles back, but says he'll exchange them if I'm not happy after a few days (but I'll have to pay another $25 per tire to get the A/S's shipped from somewhere back east to here in So Cal).

I drive away grumpy. I do my "standard" tire mileage test -- a 5-mile freeway portion of my daily commute @ about 70 deg F, engine warmed up, battery charged to nominal, cruise control @ 55 (actually 88 kph), plus a 2 mile neutral coast at the end of the run. I look at the dashboard mileage and the final speed (at the end of the coast). Here are my results:

View attachment 69330

Well by gum, these ES's are OK so far. One significant advantage - they're rated 91H, max pressure 51 psi (instead of 89T / 44 psi for the A/S's). And of course I pump them up to the max. So I've had enough of this. I'll just keep driving on the ES's. I guess we'll see if the treadwear is really as bad as a lot of folks are saying.
Click to expand...

I'm not wishing to rain on your parade but running at 51 PSI (for the weight of the car) could be problematic -
*Harsh ride
*Your tyres will wear very fast in the center, seriously reducing your tyres' lifespan.
*More likely to suffer a blow out at speed
*Stopping distance reduced
*Reduced grip
Click to expand...

I was going to say the same thing, particularly running 51 PSI is going to kill tread life.

MJ50 · Oct 26, 2014

will try federal next time...

Energy Efficient Tyres

dolj Senior Member

MJ50 Junior Member

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Energy Efficient Tyres

dolj Senior Member

MJ50 Junior Member