Hi folks, I replaced my OEM wheels ~2 weeks after buying my Prime new in 2020 to 17x5 aftermarket wheels (Flow One 17x8 18.4lbs each). The car only has 25K miles total on it as of today. Rotating my tires for the second time, the tire shop noticed the inner tread on both rear tires was disproproptionaly worn. They do not do alignments at this shop, but the tech recommended getting one, or risk having to replace the tires before they even had 30K miles on them. Since it was a new car, I did not even think that the wheel change would require a new aligment. The car handles great and feels great, and the front tires are wearing evenly. so I am not sure what may be out of wack here. I have the OEM wheels stored in my basement, and if folks think the only solution is to re-install these I can certainly do this. The reason I changed my wheels is that where I live Portland (Oregon) the highways have deep wear grooves from studded tires and unfortunatley these grooves fill up with rain and the OEM wheels fall into these grooves and hydroplane on the pooled water. Its a little un-nerving to hit one of these grooved spots at 60 mph and feel the front end get loose for a second or two! Changing to a 17x5 wheel/tire setup helped a good deal with thethis issue, so I would prefer to keep this combination. My appointment for an alignment is schduled for next week, so I was hopng to get some feedback on whether an alignment works on the rear end of the 2020 Prime and that it would help resolve the uneven tire wear. Many thanks in advance for the feedback from the forum members.
Sorry, whenever you buy a new set of tires, the alignment should be checked. This protects your investment in a new set of tires. If there is an alignment problem, you wouldn't tear-up your new set of tires. Did you get the alignment checked before switching tires and rims to see if that was the actual source of your hydroplaning issues? You changed both tires and rims from it's OEM specifications. Why would you think that everything will automatically align itself. An alignment check should have been done. Sorry if this seems harsh, but live and learn.... FWIW, some things on the rear axle may be easily adjusted, other things may require some parts
I stated 'rear axle' meaning both rear tires - you've got independent suspension back there, so you'll need a 4 wheel alignment. https://www.cars.com/articles/when-should-you-get-a-wheel-alignment-1420681259841/ Depending on how bad the wear on your current tires are, I'd suggest moving the good front tires to the rear to get a more accurate alignment back there. The worn inner tires will throw off the alignment, that's why you do an alignment check when you replace tires. FWIW, Toyota recommends 5K mile tire rotations not every 10K miles.
Thanks for the clarifications. Will definitely schedule future rotations at the 5k mark. The uneven wear was caught a bit too late to simply rotate the tires with the inner rear tires both having ~2/32 tread left. The rest of the tire had >6/32 left. The front tires were also evenly worn to >6/32. I opted to have the tires replaced on all 4 corners and recognize my mistake of not having an alignment when I swapped the OEM wheels/tires. Car is scheduled to be aligned at a dedicated alignment shop next week. Interested to see how much the aftermarket wheels and tires changed the alignment specs and to see if it correlates with the uneven wear. I'll post the numbers when the job is completed here to help anyone follwing this thread and possibly in the Aftermarket wheel section of the Prius Prime Modification forum.
Here's a comprehensive thread on wheels for the Gen 4 Prime. There's a lot of stuff covered in the thread, so I wouldn't recommend you try to take it all in at once. Aftermarket Wheel Fitment Guidelines | PriusChat You didn't mention which model Flow One, but you might want to go back and check those wheels offset, because there is a recommended offset range. This thread caught my eye because I like leaning new things about the car and I'm sure not expeienced with rear wheel negative camber. The only real experience I have with alignment are years ago in a 72 Charger with front control arm ecentric adjusters and a 2002 civic with passenger side lower control arm damage that the alignment guy couldn't get within spec and told me a needed a cam kit. (It really needed a new lower control arm, but I didn't figure that out for quite a while after that alignment and I didn't know what a cam kit was anyway. Here are two tubes that might help you get a clearer idea of what might be going on with your rear wheels. honda prelude in this one bmw x5 in this one
@vvillovv Thanks for the post. I actually had read the aftermarket fitment guide and selected the Flow One Spec F2 wheel (17x8, ET45, 18.4 lbs) following the size recommendations in that guide. Does anyone have the factory Castor and Camber recommendations for the 2020 Prime? It will be interesting to see how far from factory my alignment is currently set at.
Sometimes someone or another has those specs from the repair manual and share them. Other times it's up to an interested party to grab a standard subscription of the manual and dig out the specs in the book. Mostly, when doing the work DIY, but not always. Toyota Service Information and Where To Find It | PriusChat
To follow up, I just returned from having a 4 wheel alignment done at Beaverton Toyota (Beaverton, Oregon). When I dropped the car off, I shared with the Service Advisor that the rear tires were wearing unevenly with the inner 2' of tread being abnormally worn and that the tire shop recommended an alignment to prevent the new tires from having the same thing happen. The service cost $170 plus and additional $8.90 shop fee for a total of $178.90. The alignment sheet is posted below. When the car was done I asked to see the alignment sheet and the service advisor immediately shared that camber is not adjustable on this car. I asked how their adjustments will prevent the uneven tire wear and she stated that the toe adustment will fix the wear. . She also stated that they recommend an annual alignment. To the forum folks: Is it true that camber cannot be adjusted on a Prius Prime? And do folks actually get their alignments done annually? The advisor was also unable to provide the factory alignment specifications for car even though I asked if she could get these while I was dropping it off. All she could say was if it is green on the sheet you are within an acceptable range. I guess one keeps the provided alignment sheet to know each year what needs adjusting. The experience did not instill confidence that they provided the a service that will insure the new tires will wear evenly as it seems that only a small amount of adjusments were done for the rear wheels : Toe (Left -.03 degrees to + 0.11 and Right +.05 to +.12) Total toe seems to be the largest change going from -.04 to +.23. Hopefully this sheet will help someone else. As to the additional shop fee, it was not included in their initial quote for an alignment. Asking what the fee was for, I was told that was for towels and supplies and they insisted it was legit.
Is it true that camber cannot be adjusted on a Prius Prime? Don't know, but you can call other tire n wheel shops that has an alignment machine. Those are usually the better high end shops in the area that can do adjustments for specialty rims they sell and install on a cars. I'm pretty sure a body shop with an alignment machine can get them into specs. And do folks actually get their alignments done annually? No, I don't - unless I hit the curb or go through an unusually deep pot hole and the car starts feeling squirrelly. The advisor was also unable to provide the factory alignment specifications for car even though I asked if she could get these while I was dropping it off. It's unfortunate that now-a-days people let computers do all the thinking for them. Nobody looks up specifications anymore. FWIW; I could have kicked the tire to get you that 0.03-0.04 toe adjustment you needed. no kidding.... How did the rear left Camber go from -1.8 to -1.9 with the toe adjustment - if camber couldn't be adjusted?????
I read the post in the other thread first and started to reply. i'm glad I got stuck looking for a year old post about continental tires that have wear indicators ( I commented to that post how much I liked that feature on that set of tires ), but I couldn't find it and decided not to post my reply. The reason I'm glad is because I was going to comment that there was not alignment report with it. I don't agree with the yearly alignment report, but that is normal stealership service writer behavior these days and was probably in part due to sharing your concerns about the abnormal wear with said service writer. Key here is ( imo ) that your alignment was done and the report shows it's in spec. If they couldn't get it within spec on all 4 wheels, than you'd have reason to look deeper. Remember you have non stock wheels and depending (probably a good thing that you didn't mention that to the service writer), I hope ! Or the price of the alignment might have gone up. I was thinking of the time I had an alignment done and the tech couldn't get all four wheels in spec. It wasn't a new car and I lived it for a year or two, but found out eventually while doing my own inspection exactly why the alignment couldn't be put in spec. The lower control arm was bent, missed by both the dealers shop while replacing other front suspension parts and the alignment tech while doing the alignment. Yeah $180 for an a 4 wheel alignment might sound like a lot, but believe me it could have been way worse.
