Changing tyre size.

[clubbyr8]

I'm thinking about changing the tyre size on my troll. At the moment it has the factory 17" alloys. I thinking of going to 16" and putting on 285/75R16 BFG on steel rims. The tyre diameter will go from 789 to 834 mm. What will be affected if I do this? I know nothing about suspension, will anything need to be modified? Thanks in advance... :)

[MEGOMONSTER]

These tyres fit on a GU with no lift required. Your speedo will be out a little. Stretches GU was out about 3 k's at 100kph when fitting 285's. Where as SAMs GU was corrected to 100kph when fitting 285's.

I also went to a 16"rim but fitted 305's and my speedo is out 4k's and has less power then before. EGT's also went up fitting larger tyres.

[threedogs]

thats only 22.5 increase in diameter. if you have like most a 2" lift you will be fine.
your fuel usage will go up slightly. 285s on mine the speed is spot on if I fit my 305s I need to slow down a tad.
I had no problems with my EGTs, You'll also notice a bit less power as your turning bigger tyres.
Brakes might need an upgrade at some stage as you are trying to stop a pretty big rolling mass.
99% run this combo you want to do and love it

[Agronaught]

I've only just gone up to 285's and to be honest the car feels better on the road (IMHO).

I have the TB48 and haven't noted any power issues as noted above and if anything I'm running at lower rpm's than before the upgrade (265's). Too early for me to comment on fuel usage.

The speedo is out, but its marginal. possibly 5km/hr @ 100.

getting 16" steel rim's to fit was a pain in the proverbial due to the larger calipers on the tb48, wound up getting the Kings with a -23mm offset as everything else I tried made contact with the calipers. I'll be giving these tyres their offroad christening in 2 weeks so we shall see how it goes ;)

J.

[SG1]

This is exactly what I want to put on my GU, BUT when I bought the vehicle it had brand new 265/75/16's on BFG A/T, they still don't have 5k on them so cant justify doing the changeover yet price wise tho still want to..plus I don't have a 2' lift and think will need it to fit them.

[Agronaught]

I think they would fit, without a lift you will be rubbing off road.

[clubbyr8]

I think they would fit, without a lift you will be rubbing off road.

So if I don't get a lift, the tyres will rub?

[Agronaught]

There is a chance, and not all 285s are the same size.

[clubbyr8]

Well I got them fitted today, had to remove the front mudflaps as the tyres rubbed a little. Speedo is out but I use the gps as it's more accurate. The rear wiper will be removed tomorrow, as the bigger tyre is pushing on the shaft, it's pretty useless anyway. There doesn't seem to be any road noise at all, which surprised me and the car just feels better to drive, can't wait to take it off road. It looks pretty mean too.... :)

[Clunk]

Well I got them fitted today, had to remove the front mudflaps as the tyres rubbed a little. Speedo is out but I use the gps as it's more accurate. The rear wiper will be removed tomorrow, as the bigger tyre is pushing on the shaft, it's pretty useless anyway. There doesn't seem to be any road noise at all, which surprised me and the car just feels better to drive, can't wait to take it off road. It looks pretty mean too.... :)

Instead of removing the wiper, just get a spacer

[the evil twin]

snip...
The rear wiper will be removed tomorrow, as the bigger tyre is pushing on the shaft

Thats odd for 285's, what offset rim are they on?

[clubbyr8]

Thats odd for 285's, what offset rim are they on?

Rims are - 13, didn't think about a spacer, I'll look into that....

[Agronaught]

I've got the kaymar rear door tyre bracket and antenna mount so that wasnt an issue.

[BigRAWesty]

Rims are - 13, didn't think about a spacer, I'll look into that....

If it's touching the wiper I'll assume it's hard on the door also?

[clubbyr8]

If it's touching the wiper I'll assume it's hard on the door also?

Just looked, it's not touching the door anywhere, and the tyre edge is just touching the wiper, these BFG KO's are pretty chunky on the edge....

[BigRAWesty]

Well I've sent ya a pm. If you want to go down the spacer line we may be able to sort out a solution