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Re: Replaced Ecopia's with Michelin Defenders

Posted: Wed Oct 15, 2014 1:05 pm
by Moof
I went with Michelin Premier A/S's. Despite running 42/40 psi I dropped from my typical 4.5-4.8 mi/kWh for my commute to 3.9 mi/kWh for the same route over the last few days. Hopefully that will creep up to something better. I only did 52 miles yesterday from an 80% charge and hit the LBW despite a couple hours of level 1 charging in the middle, amazing how little it takes to kill range.

I definitely like that they are quieter (almost no road noise at 55), and they under steer less on wet corners, but I can't say I've had any earth shattering ride improvement, just a little nicer.

Re: Replaced Ecopia's with Michelin Defenders

Posted: Wed Oct 15, 2014 2:47 pm
by mwalsh
Moof wrote:I went with Michelin Premier A/S's. Despite running 42/40 psi I dropped from my typical 4.5-4.8 mi/kWh for my commute to 3.9 mi/kWh for the same route over the last few days.

I just read a couple of your other posts and realize now that you bought pre-owned with worn out Ecopias. I was wondering how on earth you managed to go through a set of tires in under 3 months. :lol:

Re: Replaced Ecopia's with Michelin Defenders

Posted: Wed Oct 15, 2014 4:19 pm
by hill
Hey . . . . their Ecopias . . . . it MAY actually be possible in that short a time !!
:?
Gawd I LOVED the day I finally got rid of those things. I had to nurse them like the old lady champion easy driver just to get 32K miles out of 'em. Compare that to the Michelin Hydroedge's we had on our Prius ... that had over 100k and you'd be hard pressed to think they were even 1/4 worn. I think that's why Michelin stopped making the Hydroedge - they'd last so long you seldom go back to the tire store! Still - we replace the Ecopia junkers with Michelins and never looked back. 13k on 'em so far, and we never looked back.

Re: Replaced Ecopia's with Michelin Defenders

Posted: Thu Oct 16, 2014 9:20 am
by MajesticLeaf
Does anyone know if you are required to use "eco" tires if you replace your tires on a leased Leaf? I read that on another forum and have not been able to confirm. Apparently someone got charged when they turned in their Leaf because they didn't have special "energy efficient" (or "eco") tires, like the Ecopia.

Several have stated in this string that tires become more efficient as they wear. I don't think this is correct. Tires are more efficient if they have less surface area touching the road. As they become bald, more of the tire is touching the road causing increased resistance / friction. I think what most people are seeing is perceived improvement caused by slightly smaller tires. As tires wear out, they have a smaller circumference. Your odometer may say you went 100 miles, but you really only went 98 miles (the smaller tires had to spin more times to go the same distance, tricking the odometer). Likewise, you may think you are going a little further per KW, but you are not. So, for those that think their new "non-eco" tires will eventually catch-up to the "eco" tires in efficiency, I am guessing you will be out of luck.

One other note ... the dealer told me the Ecopia (and other "eco" tires) use lighter materials to reduce weight and improve fuel economy / range, which is another reason they wear out so fast. That said, I still think the main reason the Leaf tires wear out so fast is due to the weight of the batteries. A friend of mine that has a Tesla had to replace his tires at 16,000 miles.

Re: Replaced Ecopia's with Michelin Defenders

Posted: Thu Oct 16, 2014 11:51 am
by garsh
MajesticLeaf wrote:I think what most people are seeing is perceived improvement caused by slightly smaller tires. As tires wear out, they have a smaller circumference. Your odometer may say you went 100 miles, but you really only went 98 miles (the smaller tires had to spin more times to go the same distance, tricking the odometer). Likewise, you may think you are going a little further per KW, but you are not. So, for those that think their new "non-eco" tires will eventually catch-up to the "eco" tires in efficiency, I am guessing you will be out of luck.
That's a good guess, and is certainly part of the explanation. But there is more to it.
Tires are more efficient if they have less surface area touching the road. As they become bald, more of the tire is touching the road causing increased resistance / friction.
That effect is outweighed by other factors:
  • A thick layer of tread is able to bend a lot more than a thin layer (called "squirm"). This bending increases friction.
  • A worn-out tire weighs marginally less than a new one.
reference

Re: Replaced Ecopia's with Michelin Defenders

Posted: Thu Oct 16, 2014 12:21 pm
by DeaneG
Just for one data point, I replaced my 33000 mile, 3.5mm-tread Ecopias with a new set of the same tires from Costco, and found no observable change in efficiency.

Re: Replaced Ecopia's with Michelin Defenders

Posted: Thu Oct 16, 2014 12:35 pm
by LeftieBiker
While we're talking about lease turn-in tires, are snow tires allowed? I'd like to use the Pirellis for that, and sell the almost new Ecopias.

Re: Replaced Ecopia's with Michelin Defenders

Posted: Thu Dec 18, 2014 1:13 am
by patrick0101
The stock Ecopia tires lasted just over 31,000 miles for me. When the dealership refused to rotate them because they were so worn, I knew it was time for new tires :) I bought Michelin Defenders based on their Consumer Reports rating. Others have reported a reduction in range (at least temporarily).
Stanton wrote:...I'm seeing 10+% WORSE range out of the Defenders (low 4's vs. high 4's).
I have been driving on them for 5 days now and I have gone from 3.7miles/kWh to 3.8miles/kWh. So my range has actually gone up. The old and new tires were similarly inflated (37psi), so that is not the cause. However, I don't think this is because of the tires. It has warmed up and rained less compared to the first 2 weeks of the month that I am comparing this against. And I might be driving a little lighter footed since I knew that I was monitoring the new tire performance. So, for me the difference in efficiency is in the noise and these tires are just as good as the stock tires (but rated for longer life).

Re: Replaced Ecopia's with Michelin Defenders

Posted: Sat Dec 20, 2014 8:53 am
by hillzofvalp
I have a set of these defenders on order from Costco. I use my leaf for Lyft full time, so I'll probably be putting 60k on them in 2015. I am not terribly worried about the efficiency hit (although I'm fairly convinced that it is based on circumference constant in computer) especially since you can pretty easily regain 5% just by hypermiling more.

I also am anticipating a battery replacement in 6 months (just in time for summer heat) at or around 60,000. Because of this, I feel like I can tolerate a 2 mile reduction in range for 6 months and then when I get my new pack it won't even matter much

Re: Replaced Ecopia's with Michelin Defenders

Posted: Sat Dec 20, 2014 1:35 pm
by minispeed
hillzofvalp wrote:I have a set of these defenders on order from Costco. I use my leaf for Lyft full time, so I'll probably be putting 60k on them in 2015. I am not terribly worried about the efficiency hit (although I'm fairly convinced that it is based on circumference constant in computer) especially since you can pretty easily regain 5% just by hypermiling more.

I also am anticipating a battery replacement in 6 months (just in time for summer heat) at or around 60,000. Because of this, I feel like I can tolerate a 2 mile reduction in range for 6 months and then when I get my new pack it won't even matter much

I'd strongly recommend against these tires if you're going to do a lot of driving. They were put on a lot of prii when they first came out, around that time the energy saver A/S was out of stock which has been at or near the top for any tire on the prius in north America for a while. It's also the tire that Nissan put on the leaf in the 17in size. They don't make it in a 205 55 16 (24.9in) but they do make it in a 205 60 16 (25.7in). My cousin is running that size on his leaf for winters and there are zero rubbing issues. Considering the leaf will run 25.5in stock 17 in tires it's only .1 in more up into the wheel well and a touch narrower than a tire fitted stock.

However Costco may have issue with fitting it as they are anal. If you tell them your car has the 17s as original at 25.5 they should see it's within spec.

The tire is also 2lbs less and since it's not a low profile it will probably be cheaper (just checked tire rack is the same price for 20560 but P20560 that does 51psi is $4 more but has a lower load rating). A large diameter tire will have a lower rolling resistance than a smaller one. It will go over bumps more smoothly but since it's a higher load rating it may not feel smoother (a higher load rating is also an advantage to rolling resistance). The larger diameter will mean your energy usage is under what you actually used. For example it will report that you got lets say 5 miles/kWh however for the actual distance would travel if you held it steady to use that 1 kWh you would have actually gone 5.16 miles so your real world efficiency will improve.