Buying 17" Wheel & Tyres

[NEED4SPEED]

I am thinking of replacing my standard 15" alloys with a set of 17". Now I'm currently running the standard 225 at the rear and a 195 at the front. I'm putting them on a 1997 MR2 UK GT-T Bar. Can anyone suggest the best size tyres for a set of 17" on this car as I've heard all sorts of different stories?

[Bibbs]

215, 40 17's on the front and 235, 40 17's on the rear .. both will fit a 7J alloy ..

[EarL]

Bibbs,

Does that mean I can put 235's on my rears (they're the same width as the front)???

I have 205's all round at the mo.

[ZeroBlade]

Bibbs,

Does that mean I can put 235's on my rears (they're the same width as the front)??? 

I have 205's all round at the mo.

dude you DON'T want same all round on the 2, dangerous to say the least!!

by stock standard i think its a 20 in size diff between the fron and the rear (larger on rear).

-Z

[Jimlad]

215 front, 235 rear is the norm for 17's.

[Bibbs]

If you have the same size the rear as the front, the rear will have less grip than Toyota designed ..

Therefore you'll oversteer quite a bit .. good for track days, not so good for wet morning, hungover on the way to work ..

[Jesus]

My name's Bibbs... I'm an alcoholic!!! ;)

[Bibbs]

I'd like to deny it .. but I'm sat at my computer with a pint .. and I've got 5 empty pint glasses on my desk in the last week ..

[Jesus]

Don't worry... I'm in the same boat... so much alcohol to be consumed at JAE... staying from Friday to Sunday.

...at risk of hijacking a thread again... yeah, I'm running 17x7J front with Goodyear Eagle GSD3 215x40x17 and 17x8J rear with Goodyear Eagle GSD3 235x40x17. Both front and rear wheels ET35 offset.

Don't go any bigger on front really (tyres) as tramlining will get REALLY bad. Hard enough to drive in the first lane of the motorway as it is.

Can fit different width tyres on 7J rims but obviously better to have the rim width increase as tyre width increases.

[EarL]

Bibbs,

Does that mean I can put 235's on my rears (they're the same width as the front)???  

I have 205's all round at the mo.

dude you DON'T want same all round on the 2, dangerous to say the least!!

by stock standard i think its a 20 in size diff between the fron and the rear (larger on rear).

-Z

Dangerous??????? How???

It handles like it's on rails! I'd like to get some wider ones on the back, but I don't consider the car as it stands to be dangerous.

The only reason I haven't done so before is the wheels (Koenig Imagine) are the same offset as the front.

Can you explain how it's dangerous?

[Bibbs]

because on the limit the rear end will have less grip than Toyota designed ..

As I've said ..the car was designed with 20 differance ..for very neutral handling .. too small on the read, very oversteary, too small on the front very understeary ..

[ZeroBlade]

yup, yup, dangerous cos u'll be spinning, twirling, pirhouetting like a ballet dancer on speed!

-Z

[DeusMR2]

if you think it handles like its on rails now wait till you put the proper size tyres on! But yeah having the same size all around is very dangerous, lhave read loads of stories about accidents caused by people not knowing about the 20mm difference (Usually in the wet)

[EarL]

225's it is then guys! :D

Cheers for the advice.

[Rookey]

What does this 7j and 8j mean?

Cheers

Dave!

[NEED4SPEED]

Cheers everyone for your help. I went to Halfords and the guy at Ripspeed said that you should have a 205 40 17 at the front and a 215 40 17 at the rear!

I said I already have a 225 at the rear on a 15" why should I have a narrower tyre at the rear by upgrading to a 17"??!

I heard about the 235 at the rear and mentioned this but he was not sure....typical! Thats why I thought I would get a proper professional answer from this site. I think I will go to a supplier for the wheels and tyres at a place were they know what they are doing.

[Jesus]

What does this 7j and 8j mean?

Cheers

Dave!

7J and 8J and so on are referring to the width of the wheel itself, not the tyre.

NEED4SPEED, there is a wheel/tyre sizing matrix which gives you the necessary size tyres for different diameter wheels. Essentially you are aiming to keep the overall diameter of the tyre the same as the stock size on 15's or 14's (earlier cars). Therefore, if you want to use a 17" rim, the matrix implies you will need a 40 profile and 215 width to match the stock front overall diameter, and a 40 profile and 235 width to match the stock rear overall diameter. This is why most people will tell you to use 215/40/17 on the front and 235/40/17 on the rear. This will also give you the correct proportions of front to rear tyre widths for optimal handling.

If you went for a 225 on the rear you would need to go for a 45 profile, and this doesn't give you the correct overall diameter. If your overall diameter is out by even a couple of millimeters it will affect the circumference of the wheel quite a bit and hence throw your speedometer and odometer out... let alone your acceleration.

Hope this helps.

[dj_davo]

remember though that the original sizes are 195/55 front and 225/50 rear making a 30 difference, so in reality u could go 215, 245, though i dont know anyone that has?

stick with the 20 difference, it seems the most widely used and trusted.