Which LRR's have the least rolling resistance?

Same tire pressure in the new tires as the old?

 

The weird thing is: Bridgestone Ecopia EP422 Plus IS one of the OEM tires. Except: it's a made in Japan version. There's also a version made in the US, and a third made in Mexico. There are variations in each tread pattern. The MIJ version is very distinct, quite a bit different pattern. The US and MEX versions are similar, but vary in number of rows. All three have different wear indexes. Maybe rolling resistance is different too??

 

Unlike UTQG rating for tires, there is no industry standard for LRR that I know of. Company calls their tires LRR by injecting orange oil or green stuff or something else. Most of fuel efficiency claims they make are internal testing not verifiable by any standard testing. And if the same tires are used by two different people on same model of car, you are likely to have two distinctly different mpg results. I have used LRR tires on all of my three hybrid cars in the past and present. But for my next set of tires, I am going to disregard the LRR (or fuel efficiency) criteria for selection. I want most comfortable tire with decent handling and wet traction. I have dedicated snow, so winter traction can be ignored.

When you do cost analysis comparing LRR vs non-LRR, the difference is so small at current gas price, it just is not worth it. Here is an example of what I found out by comparing various tires I was considering. Even if there was 8.3% loss of mpg from OEM tire (from 60mpg to 50mpg), at current price of $3/gal and annual mile of 15000 miles driven. The overall cost (tire cost + gas) per 1Kmile difference is less than $6.

 

I noticed that Costco sells two different versions of this Bridgestone tire. All of the "comparisons" on their page are the same except one has a 1/32" deeper tread depth. I did not notice any country of origin on the Costco website. Same price...

 

generally, you can't beat the oems, but a few have similar rolling resistance and other improved features.

i like my michelin energy saver a/s. no change in mpg right from the get go. much quieter and smoother. but i don't know about tread wear, handling, snow/ice/rain and etc.

 

If you look at Tirerack you will find specs for two versions of Ecopia 422 Plus with distinct tread patterns (one 5 ribs, other 4 ribs), but according to the spec they have same tread depth of 11/32. I have had both of them on my Gen3 and HCH. Very good mpg, but treadwear was nowhere close to what they warrant them 70K/5yrs. I got less than 30K from one of them (I think made in Mexico one) and awfully noisy toward the end of service.

https://www.tirerack.com/tires/TireSearchResults.jsp?tireMake=Bridgestone&tireModel=Ecopia+EP422+Plus+%28H-+or+V-Speed+Rated%29&width=195%2F&ratio=65&diameter=15&cameFrom=selectSize&partnum=965HR5EP422PLV2

 

Note the "5-rib" and "4-rib". As I recall, someone here even ended up with a couple each. Raised hell and the tire shop fixed it. Another Priuschatter, who got the 4 rib version, was a bit dismayed by the wide spaces, odd looking.

Again, the MIJ version is really different: has more diagonal in the pattern, and smaller gaps.

 

Different max pressures, wear index, what's not to like, lol.

 

Me, me, me...

It was my FIRST post on PC.
Feedback of Ecopia EP422 plus? | Page 4 | PriusChat

 

It’s unfortunate the government doesn’t rate the things and plaster it alongside the weight and grip ratings

 

How many tanks have you been through since changing?

New tyres need running in as well, but 1000km I think they say they should be run-in.

New tyres will have a very small rolling diameter difference (because they're not worn) - as may different brands. Is the speedometer reading the same against your SatNav? But I'd be surprised if it's 12% difference.

 

Years ago when the Gen 2 was the new Prius Consumers Report tested about five low RR tires and the one that won was the tire that came stock on my Prius the Goodyear Integrity. They gave great gas mileage but didn't wear well and terrible traction. The Traction Control light was always on it seemed. Gas mileage dropped when I put Michelin Energy Savers A/S and more withe the third set of no name tires.

 

I wouldn't panic on one fill - I track all my fills, and have had some which were inexplicably low (or high) by up to 15% - I guess maybe often because you've used a different petrol pump and it's cut off much later or earlier.

I'd wait till your next fill before you even think about it - if that 2nd fill is low, then look into it.

 

The temperature chane is a big deal to gas mileage. All mechanical things in cold weather are affected, batteries are less efficient with weather change and tires don't roll as easy and who knows what changing to winter blend gas does to gas mileage.

 

Yeah all of that is pointing in the same direction.

I'd speculate if you stay with them, it'll be equal parts:

1. rolling resistance improvement with break-in.
2. adaption, hypermiling harder.
3. acceptance.

Can't recall if I've mentioned: can your tire place get Bridgestone Ecopia EP20? That's one tire I found that gave very good rolling resistance from the get-go. They only come in 198/65R15, and they're a common OEM tire, were one used by Toyota on 3rd gen Prius with 15".

 

I think this response nails it. I'll bet your mileage would be down almost the same amount even if you hadn't gotten new tires. My own mileage went down 10% or more since the fills prior to early November. Cold weather is a huge variable, and pretty much masks everything else except trip length.