I was just told by a mechanic that the tires that we have been using are the wrong size, 185 versus 195, for our 2010 Prius. The mess up must have happen a couple of years ago, when I had all tires replaced and did not check the work. We recently had to get 2 new tires after our Prius had a flat and we went with the sizes on the car, not realizing the mistake that had been made. The two remaining tires seem to be an issue as well and there is wear on the inner tire that is causing road noise. I am not sure if this was because the tire was smaller than the car spec or some work the mechanic fixed by in the rear wheel hub. Any tips on how I should proceed would be appreciated! thanks!
I think driving with 2 tires with one size and another 2 with another size will create problems as ABS, Traction Control, etc will sense wheels are spinning at different speed. Off size tires will not cause uneven wear, so you may also want to look into alignments for inner tire wears.
Just move the smaller tires up front to wear them out faster so you can replace them sooner to match the rears. Uneven wear isn't caused by this. You may need a 4 wheel alignment to prevent that happening again on your next tires.
The difference between a 185/65 tire and a 195/65 tire is negligible. The tread on a 185 tire is 195 - 185 or 10 millimeters (mm) narrower. That's 0.4 inches narrower. The car on a 185 tire will also sit (195 * 65%) - (185 * 65%) or 6.5 mm lower. That's 0.25 inch lower. You'd be hard pressed to notice with the naked eye. The 185/65 tire size was the OEM spec on Gen 2 Prius, so drivability is essentially the same. If you ever end up needing four tires, then I'd say you might want to go up to 195/65, but if you're only changing two tires, stick with your current size. Keep all four tires the same size. And put the newer/better tires on the rear, regardless of front-wheel drive. Always have the better tires on the rear.
Well, I would check very carefully the load rating of the smaller tires. They will probably wear faster and be closer to the "limit" in load rating. If they are still "safe" then you can use them until they wear out.
Any competent tire shop would check the readily available database of specd tires. Same place each time? How many miles since the first mess up? And again, since replacement of the most recent pair? I'm thinking they take back the latest two, and get you into a set of four, the proper size. The first place in particular should be reported, that's unprofessional.
That's how I'm reading it as well. But there are a few posts above that seem to suggest some people think it's 2 smaller and 2 larger, so I just wanted to clear it up.
