Check Your Front Tire Wear

FuelMiser, I will add these comments based on my past experience as a Gen3 Prius owner, Bridgestone Ecopia Tire owner, and past mechanic for 16 years.
I believe the lack of rotation contributed to your heavy inside tire wear. I believe the suggested rotation mileage interval is every 5K miles. In my experience if you drive mountains and hills that require lots of steering input then you should try to keep to 5K interval. If your driving habits are more freeway and highway with little steering input then you can stretch out closer to 10K. With my 2010 I was rotating every 10K miles, using Bridgestone Ecopia EP422 and EP422+, and I was able to get 70K miles from 2 sets with even tire wear.

It is difficult to provide a true suggestion as to what led to the inner tire wear without looking at the condition of all 4 tires. Inner tire wear on both front tires can suggest that toe is not set correctly, tire was not properly inflated, lack of rotation, or a contribution of all factors. Having the alignment checked by a reputable shop will confirm if alignment was to blame or if other factors were the cause, and hopefully increase the chance of getting good wear out of the new set of tires.

Standard practice for most tire installations is to put the best tires on the rear of the vehicle. I believe the thought is that if you get into a situation where a loss of traction occurs you are able to adjust steering input to correct. The loss of traction should most often occur on the axle with tires that have the least amount of tread which would be the front. Excessively worn tires on the rear of the vehicle to not afford you as much correction when they loose traction.

I just this morning completed an oil change, tire rotation, and transmission fluid change on my 2018 Prius Prime. I have 34K miles on the original set of Toyo tires and they are wearing evenly. I do see slightly more outer tire wear on all 4 tires compared to the Bridgestone's but I am not surprised based on this being a softer tire. The Toyo tire only has a treadwear rating of 300 so I do not expect them to last to 70K like the Bridgestones I had on my Gen3.

My opinion is the tire shop made a good call by having you replace the 2 front tires. Have the alignment checked by a reputable shop so you know what you have. Rotate your tires at 5K intervals. Keep your tires inflated to spec. Drive safe!

 

Thanks High Mileage. You answered the question I was getting ready to ask, which was whether I should say yes to my dealer who wants to change the trans. fluid on my 2017 Prius at 72,000 miles on the clock. I am amazed at all those miles on my OEM Dunlop tires, gauged with 4/32 tread still left. Not use to this much success with OEM tires. As you said, I'm a highway driver.

 

All four of my tires are wearing much more on the inside edge. It seems that the front end is eating up the inside edges, and all four tires are worn on that edge because I'm rotating the tires every 5000. I just had an alignment done, and I'm going to get new tires. However, they said that the alignment wasn't too bad. We'll see about how the next set does, but I'm not too optimistic.

 

Unless he unmounts the tires and flips I’ve found the tires on most moderns cars to wear the inside faster inside than out in all 4 positions even with a perfect in spec alignment. Both my volt and Cobalt do so only way they don’t is if I get an independent to set off spec to zero toe.

in his case however his wear inside is excessive enough to justify an alignment, also possible an alignment isn’t enough as parts may be worn or damaged.

on my cars even though the edges wear quicker I can get the main tread down to the wear bars before the edges are eroded, whether I do lots of rotations or none I don’t get a better wear pattern

 

Previous sets of Ecopia 422+ - I'm at end-of-life on 3rd set - have been rotated regularly and experienced nice, even wear. This set I tested. I ran 35k miles (1/2 way based on previous wear) before I rotated. The now rear tires are well into the wear bars at about 50k miles while the fronts look terrific, several 32nds before wear bars get involved. Glad I tested, wished I hadn't, ya know?
A new set of four is on order (Amazon, $95/tire). The current fronts will be kept for backups since there is easily 20-25k miles left in them. I will not skip the rotation going forward.

 

I got nearly same wear on my fronts and IIRC did last rotation at 16,000 and now have about 39,000 so figure about 23,000 without rotation.
I guess I'll rotate (PIA on this car due to being so low). Reason I've been putting that off is I figure I'll get the whole thing up on blocks to install tow hitch, run trailer light wires, change ATF, maybe install custom cat-shield, maybe install 1.5" lift blocks.