Low Rolling Resistance replacement tires: Current List

I tried to put Bridgestone Ecopia EP422 Plus (VR) 205/50/16 tires on my Prius Touring and the "slip indicator" light keeps coming on whenever I hit 60mph. My old tires were 205/55/16. Stock is 195/55/16.

The mechanic tried many combinations and said these combinations work:

205/55/16 in the front and 205/50/16 in the back
205/50/16 front left and rear and 205/55/16 front right
205/55/16 all four

I assume that this means that the sensor is only on the front right and it won't take 205/50/16. Why is that?

 

Stock (in 16") is 195/55R16? I'm clueless but: I can't see how you can have problems if you put the same tires on all four, regardless of size. The warnings are due to different outside diameters, right?

 

That's correct, Stock is 195/55R/16.

I agree with you; that's why my mind is boggled. I don't know what the "slip indicator" light checks. I assumed it compared front right to front left and didn't care about the back?

 

205/50/16 is 864 RPM if I use the specs for the Ecopia EP422 Plus (H- or V-Speed Rated).

Your car wants 833 RPM and the 864 is more than a 3% difference. It's probably just setting off an out of bounds check in the computer that is checking RPM.

Said another way 205/50/16 is only 24.1" diameter and your car wants a 25" tire. You just need a larger diameter tire than you are trying to use.

I'd like to think stock was a 15" tire like 195/65/15 or if it was a 16" it was 205/55/16. Have you looked at the label on the driver door jamb to see the size listed there? I suppose I'm willing to believe that Toyota pushed the small end of usable OEM tires on your specific car.

 

I'm idly wondering why we didn't get warnings when using a temporary spare one time. Pretty sure it's OD was markedly smaller, just from looking at it. Should check though. It actually wouldn't make much sense, for the car to freak out every time you use the temp spare.

 

Temp spares are meant to be used on rear position only. If you have a front flat you are supposed to rotate a rear tire to the front and put the temp spare on the rear.

Doing that properly allows you to use any size spare in an emergency without the system freaking out.

 

It was in a rear location, fwiw. Regarding your first sentence, that does sound like good practice, but there's no statement to that effect in the Owner's Manual, just saying.

 

I checked and my 2005 Prius manual doesn't have that warning. Must have been on another car. Seems like I remember a sticker on the temp spare wheel itself warning you not to put it on the front but I'm not going to dig my spare out to check for that.

 

I can wait.

 

New Ecopias always squirm a bit especially on grooved pavement. It's a little bit like driving on an open deck steel bridge. The trick is just to drive and not react to it. I'm on my second set. Could the car be sensing this?

 

I don't have a touring model -- just the model that takes the 185 XXX tire.

But, seeing that I took the spare out yesterday and idly read all statements on the spare, as I was delaying pulling out the rear seat of my Prius, IIRC there is no warning to NOT use the spare on the front of the car.

I have in fact used the spare on the front passenger side of my Prius at least three different times. I never got the traction warning. I do always get that warning however at very BAD times, such as trying to start from a dead stop on a dirt slope, or crossing a slightly icy intersection. The whole traction/slip thing is the one thing I really hate about the car....well, that and the reverse beep, but I silenced that long ago.

 

Love my ECP 20 OEMs but should have considered the 422s. MIJ ECP 20s at 42PSI are difficult to wear out and get outstanding MPG. Only nails and razor blades do them in.
60K and lots of tread on the two that are left. The other six I special ordered from Walmart.

Anyone replace the electronic valves with plain stems and live to tell about it?

 

Never put different size tires on drive axle it may cause transaxle failure.

 

In 195/65R15 personally I'd stay with EP20. It's the ONE size they come in. I have a hunch their RR is better than EP422, or at the least equal. The new EP422 plus is getting better comments regarding RR here. Another issue with EP422: in 195 width it has an "awkward" look: one less row of tread and wide gaps, comparing to stock photos of the tread.

Regarding your last sentence, there's no issues using plain valve stems without TPMS, apart from a small warning light.

 

The answer is EASY! The spare tire is the SAME diameter as the regular tire. The difference is the tire width. Spare is narrower.
It saves depth in the tire well.

Make SURE that the spare tire is at 60 PSI. This is easily forgotten. No help if the spare is flat or even at 30 PSI.

 

Yeah, well, at least it's close. The base third gen size is 195/65R15, which has tire outside diameter of 25". The compact spare tire size is T135/8016, which yields outside diameter of 24.5". Close.

That's the impression I got, the one time I tried to drop a regular tire into the compact spare well: it didn't quite fit, rode up a bit, and then with the greater thickness, and even without the tool tray, the hatch floor was riding up an inch or two.

 

Not an issue. I generally have a portable compressor with me that works off the 12v port and a 100 PSI air gauge. Worst case my normal travels never take me more than 15 miles from home I'd have my wife bring the other car and it'd have the other portable compressor.

Being a PSI fanatic is so much easier on the Leaf. TPMS + Leafspy app and I have all 4 pressures on the dash at will without getting out of the car or undoing a valve stem cap. It even has a user settable alarm to tell me if the PSI drops below my bottom limit.

Darn, I suppose I should go check the PSI in the Prius again. I only check it every few months vs the several times a day on the Leaf.

 

Bragger

 

I just replaced my old Bravirus tires with Bridgestone Ecopias at 167654 miles. I went with standard 185/65R15 tires. The old tires were 195/60R15's I have to verify the speedometer with my GPS. Before it was off by +2 mph at 60 mph.

I immediately noticed how quiet they are. The air pressure is at the standard 35F 32R so the ride is nice. I'll pump them up higher soon.

I hope hat they will give me good mileage. Now that winter is here I am getting 45 mpg around town. Maybe 50 mpg will be too much to hope or this season, but I hope I can get 50 mpg.

 

The millage goes up after a few thousand mile break-in. I love the quite and the ride is like fuzzy slippers. Some complain about squirm on grooved highway, but this diminishes after break-in.