Ecopia EP422 tires suck

[Nubo]

In reply to DarkStar's question for me, I just wanted to make sure that people think about the consequences of their actions and realize that the collective wisdom of this list is really good, but may not be as good as the experience and controlled testing of Nissan and Bridgestone engineers.

It is almost certain that higher pressure will reduce rolling resistance, and that will improve range. We've seen graphs of that. But that isn't the only effect of higher pressure. I am trying to get people to think of more than just one parameter, not just tire life or range.

I said that there ARE tradeoffs to higher tire pressure. I don't have proof of what those tradeoffs are. I proposed a few possible reasons to get people to think. It would take time-intensive and expensive testing to prove or disprove any of those theories. Those are the kinds of things that Bridgestone and Nissan do. My point is that there's a good chance that Nissan engineers aren't absolute morons who advise us to do stupid things without a reason. It could be that there are good reasons for their recommendations.

We all make the mistake of drawing conclusions from too little data. It's true that one data point is more data than zero data points, but non-controlled experiments have very often led intelligent people astray. Some have said that they pump their tires high and they don't wear well. Others have said that they pump the tires high and they wear well. And others have said... I think we've heard every possible scenario. ...

Fair enough, but when both shoulders of each tire wear out prematurely, while the center of the tire has plenty of tread, that is not an tiny data point with limited diagnostic import. It's a huge red flag telling you the tire is not making proper contact with the road. (Absent any major alignment issues or unusual road surfaces such as the gravel mountain roads that have been discussed).

 

[EVDRIVER]

Ran mine at 50 PSI for the entire life of the tires with no abnormal wear showing.

 

[TomT]

I would never recommend that anyone exceed the maximum sidewall pressure rating of any tire. It is simply too dangerous... Yes, most may get away with it, but you never know...

Ran mine at 50 PSI for the entire life of the tires with no abnormal wear showing.

 

[EVDRIVER]

I would never recommend that anyone exceed the maximum sidewall pressure rating of any tire. It is simply too dangerous... Yes, most may get away with it, but you never know...

Ran mine at 50 PSI for the entire life of the tires with no abnormal wear showing.

I'm not recommending it but the difference is small. I believe the stock cold max is 44 so it is not much. Of course we know what prius owners hav ebeen doing for years. These tires are terrible at below the max rated PSI.

 

[dgpcolorado]

...Now that we have some ice/snow on the ground I was able to test out my newly acquired 91's ecopias. They work great and even seem quieter! Plus the 91's have a 65,000 mile warranty.

I've also been pleased with the brand new replacement Ecopias, although I only have about 150 miles on them. They are quiet and smooth and seem to handle hairpin turns fine. Haven't tried them on snow yet but may do that later today or tomorrow since my steep driveway and some of the roads here are snowpacked.

Edit: the new Ecopias did very well on snow, as expected. What surprised me is that they did well on ice too; that was unexpected.

 

[DaveinOlyWA]

I find that dealership mechanics will do 38psi, sometimes 40. Don't ask them to do sidewall maximum, as they actually have decent grounds (gauge error) to refuse.

oh ya, they have that "one time" option

 

[sredlin]

Ran mine at 50 PSI for the entire life of the tires with no abnormal wear showing.

So what was the "life of the tires" when you ran them at 50 psi, do they get closer to their 65k mileage warranty like that? I ran 40-44 depending on how often I remembered to check my original tires and they were at the wear bars on the shoulders by 25k miles but I kept them for another 5k.

And did you find any range advantages with 50 psi? Or how about any noticeable loss of traction or other negative handling issues? There seems to be at least a few folks here that feel the need to let us all know just how wrong it might be to run more than Nissan's recommended 36 psi, but I ignored that from the start and didn't have any problems over the 30k life of the original tires, the traction and braking seemed just fine to me as well, but I don't drive aggressive and race around either.

My guess is Nissan recommends 36 psi to account for any and all driving styles, and that tire pressure will maximize the tire surface in contact with the road and provide maximum traction and braking performance, at the expense of tire wear and EV range.

I've read a fair amount of forum posts of hyper-milers that report running high pressure in their tires to maximize gas mileage, and they don't seem to report any problems with 50+ psi tire pressures, but that doesn't mean there are not problems either? In my case I ran at least 40 psi for the short 30k mile life of the tires and didn't have any major problems other than premature tire wear that looked like the classic under-inflated tire wear.

 

[sredlin]

So I'm curious if anyone on this forum has run the recommended 36 psi in their Ecopia tires for the life of their tires? And if so, what was the life of the tires on their Leaf at that pressure? My guess is maybe 25k miles or less?

 

[LeftieBiker]

I would never recommend that anyone exceed the maximum sidewall pressure rating of any tire. It is simply too dangerous... Yes, most may get away with it, but you never know...

Ran mine at 50 PSI for the entire life of the tires with no abnormal wear showing.

I'm not recommending it but the difference is small. I believe the stock cold max is 44 so it is not much. Of course we know what prius owners hav ebeen doing for years. These tires are terrible at below the max rated PSI.

No, they aren't. They are probably lousy at 36psi, but at 40psi Ecopias are "ok" rather than "terrible." My housemate's Prius does fine with them at about 38psi, for that matter. Let's not let hyperbole get in the way of helpful advice.

 

[DaveEV]

I ran 40-44 depending on how often I remembered to check my original tires and they were at the wear bars on the shoulders by 25k miles but I kept them for another 5k.

There are no wear bars on the shoulders of the EP422. In fact, the shoulders will appear bald even if evenly worn when there is still 1/8"+ of tread above the wear bars because the tread depth of the shoulders does not extend the full depth of the tires.

This makes one think the tires are wearing extremely fast on the shoulders, but in reality, it's not quite as bad as they look.

FWIW, I found anything above 44-45 psi on the OEM EP422s too harsh and they did tend to trigger ABS over sharp edged bumps more easily. I tended to run 44 psi front / 42 psi rear which was OK and got 32.5k out of the tires before I had about 1/16" left over the wear bars. The shoulders sure looked bald, but they were OK. Wouldn't want to drive them in any significant water, though! I replaced them with DiscountTire RoadHugger GT Ecos (aka Kumho KH30), but I kind of wish I stayed with the Ecopia because of the hit in efficiency.

 

[DNAinaGoodWay]

I ran the '12 at 40 psi and when turned in at 22k they had the minimum 4/32 (1/8) left, and bald shoulders.

I set the '15 at 38 psi when it was around 55F outside, so when the temp dips, they're just below 36 psi according to LeafStat, and the ride feels better, so I'll run them like that, but use snow tires next winter and in '16-'17 to extend their life to lease end at 36k.

 

[sredlin]

There are no wear bars on the shoulders of the EP422.

I'm not sure what your tires looked like, but my OEM tires had wear bars just inside the block of shoulder tread where the first deep groove all the way around the tire between the center tread and shoulder tread is? And my tires wore down to those wear bars meaning completely bald shoulder tread, there was no perceived bald tread, it was like a racing slick where there was previously shoulder tread.

Of course my experience is not unlike others here, and is essentially the reason this thread with it's derogatory subject line about Ecopia tires was started in the first place. Unfortunately, it doesn't seem like there is really anyone who has suggested a tire as good or better for range at a comparable price, so I am now on my 2nd set of Ecopia tires as they made the most sense for Costco's price of $450 out the door. Good luck with your Kumho tires and let us know how they wear compared to Ecopia tires.

 

[DaveinOlyWA]

So I'm curious if anyone on this forum has run the recommended 36 psi in their Ecopia tires for the life of their tires? And if so, what was the life of the tires on their Leaf at that pressure? My guess is maybe 25k miles or less?

Taylor ShellFish Guy ran his about 38-40 PSI I think and his tires went like 80,000 miles?? When I first met him, his tires had almost 50,000 miles on them and I thought they were new!

 

[dgpcolorado]

There are no wear bars on the shoulders of the EP422. In fact, the shoulders will appear bald even if evenly worn when there is still 1/8"+ of tread above the wear bars because the tread depth of the shoulders does not extend the full depth of the tires.

This makes one think the tires are wearing extremely fast on the shoulders, but in reality, it's not quite as bad as they look...

Thank you for mentioning this again; I think it needs to be said on every page of every tire thread.

Here are some measurements from my new Ecopias

Tread depth, main rain channels: 9/32"

Tread depth, outside edge of tires 5/32"

As you said, this is why the outside edge of the tires looks bald — even though they are wearing evenly — well before the tires are worn to the wear bars (located in the rain channels). And why we see so many complaints about bald Ecopias here.

I found that driving my old tires with bald shoulders in rain wasn't a problem, the rain channels still seemed to work ok. But I wasn't trying to push them to hydroplane or anything like that. As you might expect, the dry pavement traction of the worn tires was quite good.

I generally run 40-42 PSI. The ride is noticeably hard but I drive too many high G hairpin turns for a squishy 36 PSI even if I weren't interested in maximum range. And I continue to be pleased with the snow/ice performance of the new Ecopias. For non-snow tires they are pretty good (and I have forty years of snow driving experience, so I'm not a neophyte).

 

[LeftieBiker]

Unfortunately, it doesn't seem like there is really anyone who has suggested a tire as good or better for range at a comparable price...

If 0.1 M/KWH less range isn't good enough, then I guess you're right.

 

[sredlin]

Unfortunately, it doesn't seem like there is really anyone who has suggested a tire as good or better for range at a comparable price...

If 0.1 M/KWH less range isn't good enough, then I guess you're right.

And what tire are you talking about?

 

[LeftieBiker]

From my last post in the new replacement tire topic:

"The Goodyear Eagle L/S tires I got new for $375 (for 4) are wearing well and my efficiency is close to the Ecopias - about 4.3 M/KWH. They could be better in heavy rain and they aren't aggressive for snow (neither are the Ecopias) but I'm happy enough with them. They are US-made but the temp/load ratings aren't high (also like the Ecopias). They do handle better."

I've gotten as high as 4.6 M/KWH with them on trips.

 

[ttweed]

Unfortunately, it doesn't seem like there is really anyone who has suggested a tire as good or better for range at a comparable price...

If 0.1 M/KWH less range isn't good enough, then I guess you're right.

And what tire are you talking about?

If you look back further in this thread, I also reported the same 0.1 M/kWh hit in range when I replaced my Ecopias with the Kumho Ecowings, and they were comparable in price. http://www.mynissanleaf.com/viewtopic.php?f=27&t=4370&p=344585#p344585

It doesn't look like I am going to get any more life out of them though, they are wearing at about the same rate as the Ecopias.

TT

 

[TimLee]

Taylor ShellFish Guy ran his about 38-40 PSI I think and his tires went like 80,000 miles?? When I first met him, his tires had almost 50,000 miles on them and I thought they were new!

93,000 miles
Page 1 of the new tire replacement thread.
http://www.mynissanleaf.com/viewtopic.php?f=27&t=14580&p=332274&hilit=+tires#p332274" onclick="window.open(this.href);return false;

 

[DaveinOlyWA]

Taylor ShellFish Guy ran his about 38-40 PSI I think and his tires went like 80,000 miles?? When I first met him, his tires had almost 50,000 miles on them and I thought they were new!

93,000 miles
Page 1 of the new tire replacement thread.
http://www.mynissanleaf.com/viewtopic.php?f=27&t=14580&p=332274&hilit=+tires#p332274" onclick="window.open(this.href);return false;

well, I knew it was A LONG WAY. I really was amazed. I did well with my tires but that nearly all freeway commute is what does it.

FYI; stuck in traffic on Monday so decided to test my tires and found the stopping power to be very good. It was in the low 20's so purposefully tried rapid acceleration and emergency braking on slick spots and the car does very well on uneven surfaces.

but in reality, I am sure the battery pack gives the tires an unfair advantage. My Prius which ALSO had Ecopias did not fare as well. During our record snowstorm, it sat half in and half out of our driveway for 5 days unable to move. The LEAF was able to go anywhere as long as traction control was turned off