Hey guys

I need to change my rear tyres. I've got the stock VRX rims which i think are 225/50/17. I am sticking to the Bridgstone GIII. Anywayz the guy at bridgstone told me that he recommends 235/45/17. He said they were better and are legal.

BUT


My front tyres have got new GIII"s 225/50/17 and if i put 235/50/17 at the backhow does that affect the car.

Any thoughts!!

Thanks

They are illegal...

They are illegal...

Why? considering that the guy is an expert on tyres I don't think he would be lying????

Why? considering that the guy is an expert on tyres I don't think he would be lying????

Because the VRX wheels are only 7" wide and AFAIK 235 tyres need a minimum of 7.5" wide
wheels.

Why? considering that the guy is an expert on tyres I don't think he would be lying????
You legally cant fit 8 inch wide tyres onto 7 inch rims, it will even say it on the tyre not to do it. Though some people still do because it's cheaper. I'd say your "tyre expert" doesn't know what he's talking about, unless you live in a state that doesn't inforce this rule (though i thought it was pretty standard accross australia).

also some states won't allow different size tyres front to rear,

Your speedo may be out slightly as well if you put 235/45/17's on because of the lower aspect ratio compared to your stock tyres.

Why? considering that the guy is an expert on tyres I don't think he would be lying????
He's wrong.

Insist that he consults the tyre fitters guide, he will usually mumble for a couple of moments as he goes in search for the book but usually comes back rather apologetic.

He is wrong. 235s are illegal on a 7 inch rim.

Thanks guys. Will stick to the 225. How about my other thread on fuel injectors then :D

Thanks guys. Will stick to the 225. How about my other thread on fuel injectors then :D
Don't know much about it sorry, but posted what i know :).
Anyway glad that you got your facts right in the end, stupid of this guy to recommend the tyre though. I can guarrentee you would have voided any warranty you had on the tyres and possibly risk voiding your insurance.

the 235 will fit at 7" wide rim, i had them on my 17s for the better part of 3 years.
I couldnt see it being an insurance problem if thats wat your worried about, end of the day whats 10mm gunna do besides give you alittle more traction?

It maybe illegal but thats only when they are found, until then no one knows any better.

the 235 will fit at 7" wide rim, i had them on my 17s for the better part of 3 years.
I couldnt see it being an insurance problem if thats wat your worried about, end of the day whats 10mm gunna do besides give you alittle more traction?

It maybe illegal but thats only when they are found, until then no one knows any better.
Yes, it'll fit, but how well it fits is the problem. There is a greater risk of the tyres popping
off the rim. Thats why the engineers at Mitsu did not fit 235 wide tyres to their 17x7"
wheels eventhough the 235/45r17 tyres are cheaper than the 225/50R17 tyres.

Also, chances are that the guy at the tyre centre is not aware that your wheels are only
7" wide. Service technicians are clueless to equiment specs these days. I guess theres too
many variation for them to keep track of. Last time I took my car for a service, when I
went to pick it up, the paper pusher at the counter drove my car out for me and asked me
whether I was aware of any problems with my gear shift. He said he found it difficult to
take it out of P. I told him its because its got a shift lock which requires fully depressing
the brake pedal.

It maybe illegal but thats only when they are found, until then no one knows any better.

Until you have an accident and especially if theres death involved, you'll then be up for a
criminal offence.

the 235 will fit at 7" wide rim, i had them on my 17s for the better part of 3 years.
I couldnt see it being an insurance problem if thats wat your worried about, end of the day whats 10mm gunna do besides give you alittle more traction?

It maybe illegal but thats only when they are found, until then no one knows any better.
If insurance companies can find any way to get out of paying they will. If they deem that there was a traction issue (which, well sums up a major proportion of accidents - especially on rainy days) caused by any form of tyre failure from 235s, they will turn around and void your insurance.

If insurance companies can find any way to get out of paying they will. If they deem that there was a traction issue (which, well sums up a major proportion of accidents - especially on rainy days) caused by any form of tyre failure from 235s, they will turn around and void your insurance.

Which, when there is death involved, will bring up the issue of criminal negligence.

on topic sorta... what size are stock exec tyres.. wanna work out what my speed actually is now i have changed rims and tyre size

For people who are changing to bigger rim sizes (E.g going from 17's to say 19's)
Heres a link to a good calculator for working out the right size tyres to use:

http://www.tyresave.co.uk/tyresize.html

on topic sorta... what size are stock exec tyres.. wanna work out what my speed actually is now i have changed rims and tyre size

Tyres on stock execs are 205/65 R15.

For people who are changing to bigger rim sizes (E.g going from 17's to say 19's)
Heres a link to a good calculator for working out the right size tyres to use:

http://www.tyresave.co.uk/tyresize.html

ive done a calculation on stock exec rims to the ones i have now and the percentage is -2.16%.. now does that mean that when i my speedo says im doing 100 kph i am actually doing more like 97.84?

Tyres on stock execs are 205/65 R15.


thanks mate

Actually, i have 235/45 17's on a 17x7 rims at the moment, and they do fit, and the car handles well, but technically, it is illegal to fit a 235 tyre on a 7" rim, but then again technically it's also illegal to go any wider than a 7" rim to accommodate the 235 tyre.

If you stack the car, technically your insurer can say your car was unroadworthy, but then again, as you can tell by the number of times i've had to use the word "technically" in this post, it would be very unlikely you'd get called on it.

It's ur decision really.:D

ive done a calculation on stock exec rims to the ones i have now and the percentage is -2.16%.. now does that mean that when i my speedo says im doing 100 kph i am actually doing more like 97.84?

As you are aware the execs come with 205/65/15's standard.

If you replace them with 235/45/17's (like I did onto a 7'' rim with no questions asked by the tyre shop), your rolling diameter will be only something like 0.65% (a couple of mm) out. In turn this means there will be a pretty much indetectable difference in your speedo reading because the original and replacement rolling diameters are almost a perfect match.

Putting 225/50/17's will mean that your rolling diameter is bigger than before and as such, your car will sit a tad higher and your speedo reading will be further out.

But 235/45/17's as already stated cannot be legally fitted to a 7'' rim and are more than 20mm wider than standard.

how much would 245/30/19 make on a th exec speedo

how much would 245/30/19 make on a th exec speedo
If your speedo says 100, you'll only be doing 94.76 which also means you ODO is ticking
over faster.