Gen3 Moving From 17" To 15" Wheels. What Are The Options?

[Ten Ninety]

As I will be replacing all four tyres in the new year, I am considering moving to 15" wheels for my Gen3 T-Spirit at the same time. I can get good economy even on 17s, but the appeal of even better mpg (along with possible improvements in noise and comfort) is just too good to pass up, especially seeing as I'll have a chunk of cash to put towards new wheels purely from the tyre cost savings alone.

The magnesium (?) 15" wheels fitted to the Gen3 T3 would be my preferred option but I suspect they will be far too expensive. I'm sure I saw them at £300 per wheel somewhere a while back, which is more like what I'd want to pay for four.

Do Toyota supply any other 15" alloys which would be a perfect fit, e.g. from other models? I'd prefer a Toyota wheel if I can get a set for reasonable money.

Has anyone gone for after-market 15" alloys? If so then what did you get and from where? I can only seem to find a couple of options with the correct width and offset.

I saw something about the Auris HSD not having type approval for steel wheels. Are steels available for the Prius? If so then where from?

Cheers!

[FROSTYBALLS]

I would be inclined to check the thoughts of your insurance company first - recently another member who wanted to move from 17 inch wheels & tyres to 15 inch wheels & winter tyres found that his insurance company declined the modification as the change in wheel size was a departure from the car's original spec.

See post 27 of http://www.toyotaownersclub.com/forums/topic/145281-toyota-motor-insurance/page-3

[kithmo]

IMO, the extra mpg is hardly worth the trouble and I don't think the 15" wheels are any quieter than the 17" on the Prius. I test drove a Prius Plug-in with 15" wheels and it had the same level of road noise as my old Gen3 T-Spirit.

The upside of 15" wheels is that premium brand 15" tyres are probable two-thirds the price of the 17" if not less.

Depending on how many miles you do a year, the savings on mpg and tyre prices may be offset by the extra insurance cost for a "modified" vehicle.

Also the 17" wheels look a lot better than the 15" ;)

[jgodfrey]

Hi

I recently changed from the stock 17" wheels on my T Spirit to aftermarket 15" wheels. Because I changed to all season tyres on these wheels it was not classed as a modification. Had I just swapped out the wheels with ordinary summer tyres it would have been classed as a modification. My insurer (Tesco) wasn't fussed about the wheel size difference as long as the wheels weren't bigger.

I bought a used although unmarked set of MSW 19 alloys from eBay with the correct bolt pattern. The offset is slightly different, but it doesn't seem to be a problem so far. The ride comfort is much improved and quieter. Mytyres.co.uk do 16" steel wheels for the Prius, but these don't give you quite as much cost saving over the 17s. My all season Hankooks were half the price of the Michelins, so I managed to get the wheels and a full set of tyres and alloys for not a lot more than two of the Michelins.

I can't comment on the mpg yet as I haven't done any decent long motorway runs and the colder weather is likely to have an effect, although the town driving I've done is no lower mpg wise than on the 17s.

In my mind the improved ride comfort is on the 15" wheels means the change is well worth it even if they're not as pretty as the stock 17s. I might run these all year long depending on how they perform over the next few months.....

[Ten Ninety]

Thanks for the responses. I should perhaps have said that I'm not bothered about aesthetics as for much of the year I only ever see the car in the dark anyway! Anyway, having done a bit more looking round myself, I think I have discovered the following. Feel free to correct me if I am wrong on any of these...

• 15" steel wheels do not seem to be available for the Prius at all, from anywhere. However, they are available for the Celica which apparently has the same wheel specs although the offset isn't shown for the wheels I found. They're not much cheaper than alloys in any case, which makes them less appealing.
• Second hand 15" Toyota wheels in the right fitment seem to be very hard to come by. I found one set of knackered alloys from a 90s Celica. I think I will give up on the idea of a Toyota wheel replacement.
• Wheels for the Gen1 Auris HSD are not the same as for the Prius despite both the 15" and 17" OEM versions looking like they are identical. The bolt pattern/centre bore is different. I'm sure everyone else knew this already but I was surprised that Toyota actually re-engineered the Prius alloys to fit the Auris HSD without taking the opportunity to change the style.
• Aftermarket 15" alloys do not seem to be available with exactly the same width and offset as the OEM 15" Prius wheels. The closest I can get on a 6" rim is ET40. I don't think this matters very much; it is within reasonable tolerance compared to the ET45 of the OEM wheels but it's disappointing not to get an exact match so I can tell the insurance they are exactly OEM spec.

The aftermarket option therefore looks like the most likely one for me but I have to say, I hadn't considered the possibility of an insurer refusing cover completely for a simple wheel change. I'm expecting a premium bump somewhere around £50. If it's much more than that, or they refuse outright, I'll just go for the tyres alone.

[zam.zx]

I have recently changed from 17 to 15 and have done roughly 2k miles on the new wheels. I use my prius as a taxi so I think I can give you an honest perspective on the change. The wheels I purchased were the original 15" magnesium wheels you get on the lower models. I always have a winter set of wheels for my taxi. I'm currently running Continental 1956515 winter contact ts830 which are one of the best winter tyres on the market. Luckily I own a tyre centre for the past ten years aswell so I have tried many different types of tyres on my taxis.

The biggest difference is obviously the ride quality, it is much improved over the 17" wheels. Although saying this you are going to notice this more on speed bumps more than just regular roads as the prius in my opinion has a farely stiff suspension set up as standard. It is still 'jiggly' just not as pronounced as before. Don't expect Lexus ride quality when switching over to 15. The difference is noticeable however.

As for mpg I haven't so far seen a massive difference so unless you are doing star ship mileage you will not notice.

Fir me the biggest differnce would be the reduced amount of stress and shock on the suspension components, especially when going over speed bumps and pot holes.

I may keep the 15" wheels and just change the tyres to summer tyres in a few months as I do prefer the way it drives now.

I hope this helps.

[FROSTYBALLS]

Duplicate post removed

[johalareewi]

My insurer (Tesco) wasn't fussed about the wheel size difference as long as the wheels weren't bigger.

Insurance companies are bonkers and make very strange decisions. Luckily there are several of them so you can shop around and find one that is less bonkers than the others for your particular requirements.

[johalareewi]

The biggest difference is obviously the ride quality, it is much improved over the 17" wheels.

For high milers, the biggest difference is the price of new tyres ;)

[cviclark]

I have had two Prius`s on 15" and had no complaints. I now have an Auris Excel TS HSD and only get 48 mpg against 57 with a gen3 Prius. Ride and handling fine. The extra ancillary load on the auxiliary Battery may be a contributory factor in the poor consumption as the engine starts as soon as I press the button. I also have a space saver spare (the same as the the gen3) so the Auris may be heavier. I tried to get 16" wheels & ECO tyres but the Excel is only homologated for 17" wheels so was refused insurance. I now have a list of mods to make as the car ages, all of which Toyota should have sorted out before they released the car to the public.