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View Full Version : Tyres (again!) + a bit of gearing


Berty
September 13th, 2004, 05:53 AM
Went to The LRO show saturday & I was looking for new tyres. I'm currently running 265/75/r16's on stock 16 X 7 alloys.
I was looking at 2 brands: in the following sizes.
BFG 255/85/r16, 285/75/r16
Goodyear MTR 285/75/r16, 33X12.50r15.

I'm pretty much decided that it's going to be the MTR's but I've got a couple of questions.
1. Would the 285's fit the stock 7" rim?
2. what steel rim for the 33". I think I'd need a 15x8 with 4.5" backspacing?

I also noticed the 33" looks a lot bigger than the 285, including the tread blocks. Although Goodyears data sheet says the 285 has a diameter of 32.9" & the 33 has a diameter of 32.7" :confused . The 33" definitley looks meatier though.

Or the other option is go for the 35x12.50r15 (34" diameter).
This is what I would really, really like :cool: But, I'm running stock 3.54 diffs & 1.4 transfer box with a 300Tdi & R380 manual. do you reckon the extra 2" diameter from the 35's would overgear it too much?
Oh, yeah. Truck has 2" lift.

The biggest tyre I've run so far was a mud tyre with a diameter of 835mm (32.4") & the gearing was ok with these. Although I use the truck hard offroad, it's still my daily driver so I need to retain some level of on road performance. I don't want to get into new R&P territory (financially)

Sorry if this is a bit rambling.
Thanks in advance for any input.

Brett

Mike Hippert
September 13th, 2004, 07:16 AM
Not sure they would fit good on the 7" rim, a lot of people run on 15x8 with 4.5 bs. I have seen a 200 tdi pushing 36s but I am not sure of the gearing. I would say the only place off road that you wouyld be hurt is in mud when you need to spinn the tires. How does it feel with the 265s? The 35s will make it feel a bit slower. I run the 1.4 T-case in my 90 with 35s (stock it had the 1.2 case) and I find the 1.4 case helps out a lot on the road.

Berty
September 13th, 2004, 07:57 AM
Hi Mike

it feels fine with the 265's. It felt a bit slower with the old MT's 32.4" diameter but still not bad.

Mike Hippert
September 13th, 2004, 08:12 AM
Then it's going to be a bit slower with the 35's, you may be able to help yourself out a bit if you get lighter wheels, but there is no helping the increased diameter without changing gearing. Do you do a lot of highway miles? And what type of offroading ( I know there id not a lot of rockcrawling overthere, I thought it was mostly mud)?

Berty
September 13th, 2004, 08:27 AM
I don't do a huge amount of highway miles. No motorway at all mostly a & b roads with a bit of dual carriageway. Approx 25 miles a day to work. Weekends not much road, more offroad.

You're right on the terrain. Mostly mud, ruts. ditches, water & a bit of sand. No rock in my area.

I bet you're going to suggest 255/85/r16 BFG's. I know they're a good tyre but I think they look too skinny, & looks are important too! Also they're almost into 34" diameter, so then I might as well run the 35" MTR.

Mike Hippert
September 13th, 2004, 08:53 AM
Nope! I like the MTRs, And I like a wide tire. But the MTRs don't do the best in mud. In the slick stuff, I find myself loosing traction real easy and spinning the tires in third low at 3k+ does not clean them out very much. Steering in thick mud is also hit or miss. I like TSLs and Boggers much better for mud. I do about the same miles per day as you, on the same types of roads and I have about 20k miles on mine and they are about 1/2 worn. They work very well at 15 psi on rock but you may never see that.

Berty
September 13th, 2004, 09:28 AM
I think performance wise they'll be fine for what I want. Also could be better, knowing that spinning the wheels wildly isn't going to help, might preserve the rest of the drivetrain a bit more.

If I wanted a true mud performer 35" simex extreme trekkers would be the way to go, but I couldn't live with the breakages (or the upgrades to avoid them!)

KeithD
September 13th, 2004, 10:02 AM
I have 285/75 TrXus on 7" Mangels and they fit dine - they do rub a tiny bit on full lock and the rear just hit the rubber wing extensions at full articulation. Remember different manufacturers tires at the same stated size will be slightly different in actual size. I would reiterate that if you ain't going on rock and mud is more common, ie Uk conditions, than BFG MTs are a better tyre than MTRs, they last longer AND here at least they are way cheaper. They are rubbish in snow but that's rarely an issue for you.

I doub the gearing change will be significant - I do use first on steep inclines now, whereas with 235/85s I rarely did but you don't need the momentum so much so not a problem. I think 35s would demand lower gearing though.

Mike Hippert
September 13th, 2004, 10:10 AM
Keith, I have heard that the older BFG MTs got higher mileage but the newer ones don't last nearly as long and their tread life was near the same as the MTRs. And I think the BFGs are only a little better then the MTRs as far as Mud goes, but I have yet to do a comparison or see one done in mud.

KeithD
September 13th, 2004, 10:29 AM
No one here really rates MTRs even as a mud tires - they are "traction Tires" more designed for rocky terrain....they are way better than ATs in mud of course. But even BFGs arent in the same class as super swampers or those Simex things we cant get but these things are dreadful on road, where BFG MTs and MTRs are fine. It's all about finding the best compromise for you. I havent heard about newer BFGs not lasting so well - but may be so. Some people like tires to wear faster - to give an excuse to get the latest and greatest.....l

Mike Hippert
September 13th, 2004, 10:49 AM
Agreed! "On the traction tire" they are by no mean a real mud tire.

Well I shouldn't say that I have only heard, I had a set of the newer BFG MTs on my old Ford Ranger (actually it was newer then my 90) And the tires only lasted about 25k and they were worn down to about 25% tread. I have also heard a few other people say that they don't last as long. But I may have just had a run of bad luck because I have yet to hear someone who actual has run a set with less then 35k to the same point. But I have not heard of anyone running the newer tires with that many miles. So anyone out there that has some more info?

Brett, you may want to e-mail David Buchberger

http://www.d-90.com/forum/member.php?u=64

He has a 300 tdi that he runs on 37's, but I think he has 4.54s or4.88s in the diffs.

wicks
September 15th, 2004, 02:52 AM
Go narrow and buy my set of 235 Bridgestones! ;)

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