Low Rolling Resistance replacement tires: Current List

It does not matter what size of tyres are fitted on the Prius "as far as the Speed sensors on each wheel are concerned" as long as they are all the same size. The system will work because it only checks speed difference between all wheels. As long as the speeds are the same within a small percentage it would not set any alarms if you fitted all 23 inch dia tyres or all 26 inch dia tyres. The only thing the sensors "expect" to see is the same RPM of each wheel.
The speedo accuracy will be affected by tyre size. Going up in tyre size "within reason" actualy makes the speedo more acurate since it over reads actual speed.

John

 

1. speed sensor per wheel. We agree this is a traction control / ABS trigger
2. out of bounds RPM low or high. You say there is no out of bounds. I say there might be but I'm not sure.
3. speedometer. We both agree on this, picking the right size tire will change the speedometer accuracy.

so on 2. out of bounds RPM are you sure there is no size issue that isn't coded as out of bounds no matter how small or large a tire you use on the Prius, US and UK?

In the old days before computers it was an issue of gearing and a out of bounds tire size could cause transmission or brake issues. Such as this warning from Canadian Tire at Canadian Tire - Wheels Buying Guide

With the Prius planetary gear MG1+MG2 acting similar to a CVT I think we can ignore the shift points but there is still the old "can lead to brake failure" to rule out.

Even if it doesn't cause actual "failure" could it cross a software boundary and cause a dash warning or other annoyance?

I'm not saying I know it does, I'm just saying the old rule of thumb was 3% and I wouldn't rule out the possibility of some sort of issue until someone tests it real world.

and since the poster I replied to had tires outside 3% from OEM spec and was seeing a warning I think that it is an issue that is triggering his dash warning.

To add to the fun he was in Maryland, US and was using tire sizes that aren't stock OEM sizes or anything I'd recommend as reasonable alternates. I don't agree that a 24" diameter tire is appropriate on a Prius. 26" tire I'd have no objections to if it doesn't rub (and I'm not sure that it wouldn't). I'd rather the tire be higher diameter than lower.

A typical 24" tire will have a much lower load rating and might not be safe if the Prius were loaded full of passengers and cargo or traveled long distances at high speeds.

 

Minimum speed is stationary no difference there. Maximum speed is limited electronically to 112 mph (maximum wheel speed) with correct size tyres measured at speedo. This reads high so actual speed is lower than this. Larger tyres will increase actual maximum speed but wheel speed will still be governed by speedo reaching 112 mph. Smaller tyres will reduce actual speed, but speedo will still reach the maximum 112 mph.
The car has no means of measuring it's speed other than counting the number of rotations of the wheels against time. It does not know what tyres are fitted, but calculates speed assuming the correct tyres are fitted.
All UK gen2 Prius use 195/55/16 tyres OEM. Many including myself use 205/55/16 because they are 25% cheaper, and improve stability.
Perhaps most surprisingly the rolling resistance of the larger tyres is lowere than the OEM.
Wheel size alone does not dictate the maximum load of the tyres. I have a caravan (trailer) that uses 13 inch wheels and loaded weighs over 1.25 tons carried on two wheels.

John

 

So the 2016 Prius came out and Toyota got Dunlop to make a 195/65/15 version of the tires used on the Mitsubishi i-MiEV.

You can now buy retail the Dunlop Enasave 01 A/S in 195/65/15 and it only weighs 16 pounds. Huge saving in unsprung weight and they are cheap tires.

They might not have the greatest tread life or handling characteristics but they are LRR, cheap, and low on the unsprung mass.

They are also just about perfect for fixing the speedometer accuracy on a Gen II Prius. So if you still are rocking a 2009 or older prius and you need a set of cheap LRR tires...

I'm actually going to put 15" tires on my Nissan Leaf so the plan is to buy some 15" used OEM Honda Civic HF wheels that have better aerodynamics than the OEM Nissan wheels, move the Michelin Energy Saver A/S from the Prius to the Leaf, and then put the cheaper Dunlops on the Prius.

The Prius was doing 500+ mile tanks on the Michelins so if the Dunlops drop that to 475 mile tanks if won't affect my driving much. But adding range on the Leaf will change things drastically in the sub 100 miles per charge world every mile counts.

 

I'm one week in to the break-in on a new set of ecopias, hope to see a couple of mpg improvement on my '07 once they settle in. If not I'm still getting 47mpg avg with 185000 on it.

 

Which ones did you get? Some models do not get OEM MPG and some do.

 

Just the 'standard' EP422 400 AA P18565R15

Mileage is improving, just noted mileage over the usual 47-48 mpg

 

Really want to get some ecopias for my new to me 2012. The problem is, I just bought it with new tires. Some off brand tire, they ride nice and are nice and quiet, but I want LRR tires damn it! don't know what to do. Any thoughts? Good to be back on Priuschat BTW!

 

As you can see I just picked up a set for my 2007. I did so to save my snow tires, and to get as good mileage as I can...

If your car is getting decent mileage with the off brand, it really becomes a budget question. Do you have $450-500 to put on the lrr's? You could keep the cheaper set around as a set of snow tires, or just sell them for whatever you can get for them.

 

Yes that's a very good point. I think I have a plan, my dad offered to buy my current tires. And next week discount tire is running a deal on all bridgestone tires.. I might have to hit that up!

 

How are your current tires doing? How do they feel, rolling easy or no?

 

They ride nice but I feel like the don't roll very well. Having much more difficult time gliding along in my 2012 vs my 2005 so I think it must be the tires

 

So I decided on the energy saver a/s but to my surprise they don't make them anymore! What!! Now I don't know what tire to get..

 

I can't pretend to be an authority, and since you are in a GEN II forum, posting about a 2012 model, I really can't be an authority, since I do not know what size the 2012 takes, but my local Discount Tire store is still offering the ES AS.....maybe your dealer is just giving you a line since they don't have them in stock???

I don't know. do know I need some new shoes for the car, but, hey, dry weather is here, maybe I will wait until September.

 

It looks like Michelin Energy Saver A/S is available on TireRack. Maybe they just came out with a new model?

I personally went with the Premier A/S on my 2008 Touring. about 5k on them so far, and they have been amazing. The wet traction is absurd for an all season. They certainly were not cheap, though. From my research, I think that the Energy Saver A/S is a hair more efficient, but the Premier A/S is better in every other way.

 

No need get sassy, sir. I've been a part of the Gen 2 forum for a long time and I'm not about to abandon it at a drop of a hat.. Sorry! Anyway I called Michelin north America and they are sending some Energy savers A/S to discount tire for me.

They have a new model number and discount tire doesn't it in their system. I'm glad I called!

 

I went with Michelin Premier A/S on my 2010 Because Tire Rack had it rated highest in Hydroplaning resistance, Handling, quietness , and wet and dry traction. To me safety is more important than MPG. Even though I am retired I can still afford gas.

 

I can back this up. The Premies A/S on my 2008 are pretty impressive, and this is coming from someone who drives a modified Miata with super sticky Extreme Performance Summer tires on Deal's Gap a few times a year.

 

Got my energy saver A/S tires put on today!
First thing first, they are extremely quiet, it's amazing! 2nd the side walls are softer so the car now has more body lean. 3rd Fuel economy. .. I can already tell the difference, the car rolls better and I can keep the instantaneous mpg bar at or above 50 mpg a lot more now!

Very impressed! Highly recommend these tires

 

Just got home early this morning from my near monthly 1000 mile trip From Syracuse NY to Harrisonburg & home again. According to my 'napkin figuring' I'm really impressed with my new ecopias. They seem to be past the break in period. I used 1.5 tanks going down to VA. The computer guessed 48 mpg on the way down. On the way North I estimate I'm over 50mpg, I didn't reset the consumption display, have gone over 480 miles and I'm at 49.6 avg. yeah I know, fuel bladder, fuel computer imprecise ... But it sure has been fun this weekend. I'm still on just the fill up last night in Virginia.

Trip down was day, up was overnight with less traffic. On both legs I was happy to let the lead feet pass me, cruise was set at 65-66 or so. I'm on the last pip but not blinking , will have to get gas in the morning.