Taller Tyres for NP?

[exRevHead]

How tall can I go without running into probems?

The tyre's I want to fit are Cooper ST 255/85/16 - Diameter is 844mm.

Thank for any help
Steve.

[Endorphin]

You should be aware there are limits as to how far you can increase your tyre/rim size. In NSW it no more 15mm rolling diameter and no more than 1" wider.

Given the tyre placard on your NP states 265/70-16 which equates to 777mm, going to 844 is 52mm over the limit in NSW.

You should check this out in your own state.

Mike

[brett]

Depends on what you consider problems. If your running an auto forget it. 265/75/16 cause problems with torque converter lockup, in a manual it's ok. These tyres are about 805mm so your 844mm is a big increase, this is going to cause some gearing problems.

[BazzaD]

I run 275/75R16 Cooper ST's have done 40K with them and had no problems what so ever. Speedo reading is spot on according to GPS.
Only real issue is noise, at 80 and around 110kph it's fairly loud!

[allanmac]

Depends on what you consider problems. If your running an auto forget it. 265/75/16 cause problems with torque converter lockup, in a manual it's ok. These tyres are about 805mm so your 844mm is a big increase, this is going to cause some gearing problems.

My understanding is that it is only the diesels that have that problem

By the same token, greater range to choose from in 265/75/16 & will fit a standard vehicle. Range of 255/80/16 would be very limited I think.

[Monterorider]

I run 285/75R16 on my NM. It's pretty tight fit. 255/85R16 are usually tad bit bigger. Rear is not a problem. Upfront it might run on underside of bumper bracket at full turn. But can be cured bending it a little bit as I understand.
Where did you get 844mm number? Calculated? Don't rely to heavily on that - tires of same series say 285/75R16 from different manufactures can vary by as much as ~15mm. In fact tires from same manufacturer are allowed to vary by as much as 1% in diameter. Usually it's better then that but still.... they are not exactly manufactured on the lathe you know.

[exRevHead]

You should be aware there are limits as to how far you can increase your tyre/rim size. In NSW it no more 15mm rolling diameter and no more than 1" wider.

Given the tyre placard on your NP states 265/70-16 which equates to 777mm, going to 844 is 52mm over the limit in NSW.

You should check this out in your own state.

Mike

Thanks mate - I'll check out the rules for QLD.

[exRevHead]

I run 275/75R16 Cooper ST's have done 40K with them and had no problems what so ever. Speedo reading is spot on according to GPS.
Only real issue is noise, at 80 and around 110kph it's fairly loud!

Do you know the diameter of your tyres? I couldn't find that size on the coopers website

[exRevHead]

I run 285/75R16 on my NM. It's pretty tight fit. 255/85R16 are usually tad bit bigger. Rear is not a problem. Upfront it might run on underside of bumper bracket at full turn. But can be cured bending it a little bit as I understand.
Where did you get 844mm number? Calculated? Don't rely to heavily on that - tires of same series say 285/75R16 from different manufactures can vary by as much as ~15mm. In fact tires from same manufacturer are allowed to vary by as much as 1% in diameter. Usually it's better then that but still.... they are not exactly manufactured on the lathe you know.

Are you running the 285's on the 7" wheels?
I got the 844mm from the Cooper's website - hopefuly it's fairy accurate - I don't really want to g obending anything so I might go for the 285's.

[exRevHead]

You should be aware there are limits as to how far you can increase your tyre/rim size. In NSW it no more 15mm rolling diameter and no more than 1" wider.

Given the tyre placard on your NP states 265/70-16 which equates to 777mm, going to 844 is 52mm over the limit in NSW.

You should check this out in your own state.

Mike

Just found the info and it's the same for QLD

http://www.transport.qld.gov.au/reso...on_jan05v2.pdf

[Monterorider]

Are you running the 285's on the 7" wheels?

Yes.

I got the 844mm from the Cooper's website - hopefuly it's fairy accurate - I don't really want to g obending anything so I might go for the 285's.

Some 285 do required that too. Some are bigger than others. It's just a clip which holds backcover to front bumper. You can bend it by hand. But I guess it's out anyway.
Man this side of the big pond is a bit more laxed about those issues.
They are don't look that big either.

[exRevHead]

Those tyres look like a better fit than the standard 265's - are they mickey thompson tyres?

[Monterorider]

Those are Interco SuperSwamper TrXus MT http://www.intercotire.com/site35.php

[VR4-Quest]

I just discovered why you can get away with 285's. The Inerco's you have, for a 285, are on the small side. Tread width is on 8.3" (which is narrower than a typical 265) and the OD is 32.7", again on the smaller side. They key is the tread width. The shoulder area where the tread meets the sidewall is the area that will rub. So even though these are taller (and on the small side for a 285), they are much narrower which avoids the critical area rubbing.
Normal 285's are around 9.5" wide for tread width, and 32.9" tall, which might rub a bit more! Like you mentioned, they dont look all the much bigger, cause they arent!

[mrbitchi]

Depends on what you consider problems. If your running an auto forget it. 265/75/16 cause problems with torque converter lockup, in a manual it's ok.

It does? Not in my experience..

And ExRevHead, make sure you check Monterorider's location. He's not bound by the same rules as us.. ;-)