Tire Type?

One thing: the Bridgestone Ecopia EP422 Plus on your car are likely the made in Japan variant, nigh impossible to find in North America, where there are two more iterations: a made in the US and made in Mexico. In the event of an unrepairable tire it'll be difficult to find a matching replacement here.

All three have variation in tread pattern: the Japanese is distinctly different, and at least to me looks the best. IIRC, the Mexico pattern has one more groove across the width, and they are closely spaced, compared to the wider spaced US version.

All three also have different wear index ratings, I forget the order.

 

I have the Dunlop Enasave 01 A/S. I find them to be loud on rough surfaces. Also terrible for mpg in the rain.

 

I've got the Dunlops on my Prime. Time will tell how they wear, but they are quiet, handle well, and I can detect no vibration from out of round or imbalance. It doesn't rain much here and never snows however. Gas mileage is good. I'm comparing this to my Gen 3 which had Bridgestone EP20s. Probably more the car than the tire, but the Dunlops seem better than the EP20s.

 

Mine are Toyo NanoEnergy A29, P195 65 R15. The car was built in March, 2017.

 

None other than I find it interesting that all 2017 Primes don't have the same tires. Is it possible that the Advanced would have different tires than the Plus? Since my previous daily driver was a 2009 Miata, I can't make a meaningful comparison of their tires.

 

Tires often vary, by availability, whatever. The main criteria: half-decent and LRR.

 

That's what I got on my Advanced. Honestly I have no complaints on our roads. They keep changing the surfaces of our roads so sometimes it's pot luck what sounds come out of them. Generally they aren't bad, but I haven't done any serious driving in them in the rain. Personally as soon as I feel that they get loosey goosey, read hydroplaning, I change them out.

 

Mine has Dunlops, my daughter's has Bridgestone Ecopia. I have not driven hers enough to make a comparison, but I do notice road noise on rough surfaces other than that they seem ok. Any suggestions for a quieter tire when these wear out? I am willing suffer slightly lower MPG.

 

My Toyos could be quieter--or maybe it's the car's suspension and structure that bring the noise through. Anyway, the Toyos are OK.

Tirerack.com has their Consumer Tire Ratings that include Comfort as one category; noise level isn't specifically listed. You'd have to look at three or four pages--Grand Touring All Season, Pasenger All Season, etc. And, only the brands they sell are listed...no Toyos.

 

Mine are Toyo's too, and I think the same specs...

 

Toyo

 

Mine were Toyos as well which after 30,000 miles started to slide on wet roads so I went for the Hankook 737's. They are a great tire in so many ways, they are really quiet, have a long-life (90,000-mile guarantee, and stick to the road... which is also the problem. My mpg's dropped dramatically, normally I got about 700 miles to a tank, this dropped to 650 and I was babying my driving a bit. Mavis is taking them back and I am getting the Ecopias...

 

I've previously posted about putting on a set of Bridgestone Driveguard run flat tires. The Toyos were OK until they got a puncture; I didn't like the size of the hole left by the small screw. They are a very light tire which means a thin casing. The Driveguard are heavy, so efficiency takes a hit. I chose reliability over efficiency. These 3rd generation run flat tires are OK. Decent ride & noise level. They're said to be good for driving 50 miles at 50 mph without air. They'll be junk by then, but we'll either be home, or parked and getting it patched, or on a tow truck before then.

 

Pardon me for being in the Prime forum. But I'm curious, what actually causes the sudden drop in mpg when new tires are installed on a Prius.

Weight of tire?
Tread type?
Rolling resistance?

And how does our Prius know or detect what kind of tires we installed? Doesn't make any sense to me. I've never had a decrease in mpg when new tires were put on other vehicles in the past. It would seem like a new tire with brand new tread and grip would increase the mpg... not make it go down. Is the Prius mpg computer so sensitive, that it can detect new tires??? I just don't get it. And by the way, my non-Prime 2016 has Michelin Premier 15". Noisy as all heck, but never noticed a drop in mpg. (I got rid of the OEM Toyo tires.)

 

New tires are a little "stickier", so higher rolling resistance, compared to old, burnished tires. Also, newer tires have a (slightly) larger outside diameter, so the tire does less revolutions per mile, making the car think you didn't go as far.

Interesting that your mpg didn't budge much, going from OEM Toyo to the Premiers. Premiers are available in my size (215/45R17) but I've read "mixed" reviews regarding their mpg impact. Another data point helps.

 

No expart in this, but I would think all three contribute. For example, if I change summer all season tire to winter tire, mpg get hit. I also get better mpg when a brand new tire is worn out a bit say about 5-10K. Those facts seem to relate to the friction between tire and road, less friction there are, better rolling resistance, thus lighter slightly worn tires are best mpg.