17s brake software and steering system

Prius Team told us that 15"s use different motor for the electric steering. Prius V with 17" has brushless motor.

This thread has more info.

 

I have put about 30k miles out of 123k miles in my Prius with 17" 205mm width tire. My steering wheel is still fine. The wider tire makes the turning harder so there may be some valid concern from the reliability point of view. The motor in the steering can overheat if you keep it turned all the way for a long time. The warning is mentioned in the owner's manual.

 

My BS detector is going off.

 

Well as per a different post on here, parts of the steering hardware/software is different between the 15" and 17" models they could well be right...I don't know about US law, but in the UK the manufacturer would be in their right to limit warranty on those parts affected....

I'm still in 'shock' that Toyota goes through the trouble of having different setups for such a low volume vehicle....But hey, it has me put off going down that route...

 

They'd have to prove it, but your right to use aftermarket wheels is protected by the Magnuson-Moss Act. Keep in mind that the car has many warranties covering the various components and they can't void the entire warranty based on a single incident.

 

Yes your warrenty would be void, because you are running with different size wheels than supplied with the car, meaning your drive shafts, transmission, steering will all be affected, and its possible when it was in with ur dealer that they noted the wheels on the job card for furture reference. I work for a toyota main dealer here in Ireland.

 

Ireland does not have the Magnuson-Moss Act.

Think about it, the stock 32lbs 15 incher could easily be 37lbs simply with different tires, so the different weight argument by the service guy fails.

 

To be honest I think the argument on drive shafts and transmission wouldn't stand up in the UK. I mean they are the same on Toyota provided 15" and 17" wheeled vehicles aren't they? However under UK law (and perhaps even common sense), if Toyota has made specific changes to the 17" wheeled vehicle compared to the 15" wheeled vehicle that I think it is reasonable that those specific parts and potentially 1st degree connected parts are void of warranty....

In general most cars that I have owned have not differentiated transmission, suspension nor steering parts when fitting different size wheels across the ranges...They just keep the wheels operating effect within approximately 5% of the stock....

 

So, after pouring through the numerous threads on this subject and really not finding a concrete conclusion, can someone with after market 17s on II, III, or IV bottom line it for me? That would be greatly appreciated. Thanks!

 

What concrete conclusion are you looking for? If you live in the United States, the Magnuson-Moss Act protects your right to use aftermarket wheels without voiding the warranty. It's fair game if you live in other countries.

 

Are you sure that the Act covers it, I've only taken a brief look and don't live and breath it...But the Prius situation isn't as clear cut, other 15" wheels sure fair enough...Other 17" wheels on a V yep also fair enough easy interpretation....

But taking into account the manufacturers modifactions that get done when applying the different wheels off facturary, I'd be interested to see the interpretation of how the act covers that unless you also apply the other modifications as done by the manufacturer...

It actually reads very similar to several EU directives on this subject....

 

The mere presence of aftermarket parts can't void the warranty by law and it doesn't matter if the wheel is 13" or 20", they have to prove the failure was the direct result of the aftermarket wheels. The service guy can't say "Look, you have aftermarket wheels you just voided the warranty and we can't cover it."

 

I guess that boils it down. Will 17s do harm to II-IV because of the different steering system from the V? Not sure If I came across a definite answer for that.

Thanks.

 

I haven't seen a definite answer for that either, but all those speculative, unsubstantiated claims seem to come from service people. It can go the other way, as there's a thread from someone with a 17" wheel Prius wanting to downgrade to 15" only to be told by his service manager not to do it because of the brushless motor system.

Meanwhile, lots of II-IV owners are doing just fine with their aftermarket 17" wheels.

 

I have just had it conclusively confirmed by Toyota UK that there is no technical difference. Both 15" and 17" models use the same steering setup fully, no different motors no different software etc. They are the same bar the wheels and Tyres.

The main issue will be tax qualifications but that is a whole different chat.

 

I don't know about the UK, but here the 17" wheel Prius has a brushless motor EPS. See http://priuschat.com/forums/gen-iii-2010-prius-main-forum/60065-wheels-steering-shocks-oh-my.html The update for the 15" wheel Prius to have the same EPS tuning as the 17" wheel never materialized though, according to a later post by the Prius Team.

 

Similar information given to me by my UK dealer when I was considering purchase. In the end I had the standard 17" rims and bought aftermarket 15" rims to take my winter tyres. I would have bought 15" Toyota wheels, but they were far too expensive.

Have driven both without noticing any substantial difference in the feel of the steering.