Outer Limits 4x4 Board

Hey guys, wanting to upgrade my 265/70's with something 'slightly' larger.
I've narrowed it down to either Cooper st's, or Baja radial 2's in either 305/70/16 or 315/75/16. Plz read my profile for vehicle details .

Just wanting some advice on the negative side of such an upgrade, like clearence, gearing, fuel econ., steering etc.

Any info would be much appreciated

Ok so you have a swb 3.5 V6 5sp with 4.636 diff gears and 35mm factory body lift and a 2" suspension lift ??
Your standard 265/70/16 measure out to 30.6"
305/70/16 = 32.8" (clearance no problem, fuel economy will suffer slightly you will notice some power loss)
315/75/16 = 34.6" (clearance shouldn't be an issue as long as it's a proper 2" lift but a 2" body lift would make certain, you will definitely notice poorer economy and power loss)
Remember you can upgrade to 4.90 diffs from the 2.8TDI to restore lost power.
If the vehicle is a daily driver and weekend offroad warrior on the one set of tyres I would go the 305/70/16. I think 33"s are about the limit for a IFS Paj if you want to keep reliability some sort of fuel economy and not loose too much onroad power.

315/75s will be too much for the standard gearing. You need 4.9's. I sold my 35's and will settle back to 33's.

I can testify to the drop in performance on fitting larger tyres. I have fitted 265/75/R16(31.7") which was an upgrade from the GL model of 235/75.15 (28.6"). The fuel economy has significantly increased and there is a noticable drop in power.

I am interested in the 4.90 diffs to restore performance. Would fitting the 4.90 diffs be a straight swap with a 4.636 diffs from a NL 3.5L petrol.

yeah the 4.90 diffs are a straight swap in for the 3.5l petrol diffs.

I did this in my NK 3.5l DOHC some years back.

StephenF did you adjust you speedo to suit? You have roughly increased your gearing by 11% which means you are now going 11% further thean your speedo says you are as well as 11% faster. Therefore if your odometer says you have travelled 100km you have actually traveled 111km, and if you used 13L of fuel to travel that distance you have an economy of 11.7L/100km not 13, as well as having travelled at 110km/h not 100km/h to acheive that economy. This doesn't take into original speedo error of course.
I have 235/85R16 (32") (fitted before I purchased vehicle) in place of the factory 235/75R15 (28") on my NJ 2.8TDI and have averaged 12.4L/100km for the last 110000km (best of 10.5, worst of 14.8) with a corrected speedo. A mate who also has an NJ 2.8TDI (but with only just over 100000km, lucky bugger) with std tyres an std speedo gets very close to the same economy as me.


Peter H

Ok thanks, all that info has been stored up top somewhere
Probably lean 2wards the 305's, i still want 2 maintain good drivability etc. I do a bit of track work, nothing full on, mostly city stuff, so may be the better option.
So in theory, if i were 2 take a step BACK, and go from 265's, to say 235's, i'd get better power/economy?? Damn, why cant skinny's look good and perform well!!

Hey you can always get a set of off road tyres and change them when you are intending to go off road. this would do you better in the city driving and give you the performance you want from the tyres of road. Thats what I do it is a bit of a pain but you can really feel the difference especially in the handling on road. just a thought

PeterH, Thanks for you reply there is a typo in my original post I should have said significant decrease in fuel economy. I have not adjusted the speedo yet but have checked road speed distance travelled and fuel consumption using the GPS. The amount of error in the system is 11% as when I'm doing 110km/h the speedo indicates 100km/h. With my 3.5L the drop in power on the hwy is quite noticable. As my tyre upgrade is only slightly larger than factory 265/70/16 that come on GLS models I am wondering if there is any differences in the drivetrain between the models. I recently drove GLS model with standard wheels has and it has similar power to mine when fitted with the smaller wheels. [/quote]

OK I have been thinking about some bigger rubber to replace the pitiful hiway terrains (so long as he hiway is strait and dry .. these tyres are carp) that were on it when I got it/
What is the accepted wisdom on this Vehicle is a 99 NL paj curently running 235's I want to go to a 31-32 ( Keeping it a narrowish tyre) and corrected speedo.
From memory Scott said there are different speedo gears available.

I would like to keep the economy reasonable, but accept that it will worsen, just hope it is not to much.

The GLS version came Ex-factory with 265/70R16 (or 31x10.5R16 in old money) on 16x7" alloys. You'll need flared guards to appear legal - any GLS flares NH - NK should do the job. On my shorty, 31" tyres, 4.875 diffs and a 26 tooth speedo gear put the speedo within 1% of the GPS.

With the same alloys & flares, you should be able to fit 265/75R16 (32") with little trouble. I would start with a 25 tooth speedo gear, and be surprised if you're not within 2% against a GPS.

I saw the speedo gear part numbers somewhere recently - if you have trouble finding the gear you want, let me know.

Edit: Did some calcs in Excel - if you have the 4.625 diff, go with a 24 tooth speedo to match 32s, or 25 tooth to match 31s.

http://www.outerlimits4x4.com/ftopic117 ... highlight=

235/85R16 (32" O/D) on my GLX NJ Paj (no flares needed). "Feels" better on the road then my Dad's MJ Triton with 265/70R16s, although this could partially be tyre type/brand.

Bottom line - as much as the wider tyres look cool, my "skinnies" keep making sense to me (cheaper too!!!!).

Peter H

Thanks guys.

I will drag my way through the wincaps stuff and see what I can see in there as far as speedo gears (might learn a thing or two about the vehicle while I am at it).

Will keep an eye out for some nice alloy 16's too keep the weight down and 235/85's (tall and narrow, good for the terrain round these parts)

well I just purchased a set if ebay tyres (it was an ebay pajero) 4 dunlop 672's 235/85 on ROH 16's for $315 .. pretty happy with my self for now.

nh shorty 285 75 16s goes NEARLY any where...the silverstones stick like glue on the road...and as good as tyres get in 2 foot of mud...my centrepedes are shitt compared to the silverstones...[/u][/list][/list][/quote]

Hi guys,

I am currently running 235/75/15 a/t's on factory 15x6 alloys. I am changing the rims to 15x7 and putting 31x10.5x15's instead. I have been told that there won't be any speedo difference is this correct?
Cheers

petes paj wrote:Hi guys,

I am currently running 235/75/15 a/t's on factory 15x6 alloys. I am changing the rims to 15x7 and putting 31x10.5x15's instead. I have been told that there won't be any speedo difference is this correct?
Cheers

There will be some difference, nominally your 235's are a 29inch tyre. The 31's will usually be a 30ish .. so There will be some difference.

I just went to 235/85 16's and there is a 10% difference, and a 100% difference offroad .. I love having a decent sized tyre again .. and the grip is great. was going places on the weekend in 2wd and a trailer on the back that I would have been scared of in 4wd and no trailer with the old rubber.

Petes Paj- Sounds like you have an Escape model, yours may or may not be the same but my NL Escape read about 5% over (i.e. 100km/h indicated was actually 95km/h) with the stock tyres. Now since upgrading to the 31's the speedo is reading about 1% under (100km/h indicated and 101km/h actual).

Hope that helps.

GOONA wrote:Petes Paj- Sounds like you have an Escape model, yours may or may not be the same but my NL Escape read about 5% over (i.e. 100km/h indicated was actually 95km/h) with the stock tyres. Now since upgrading to the 31's the speedo is reading about 1% under (100km/h indicated and 101km/h actual).

Hope that helps.

Mine is an NL escape .. and the speedo was pretty well spot on running 235's according to the GPS's (more than one)

Interesting, as I checked mine against a few GPS's too...

Hi Goona & love_mud,
mine is out as well running 235's almost 5klm/hr at 100, GPS says 100 speedo says 105. from what I have been told the 31's should bring this back almost spot on. Yeah I have a 2000 escape that I am slowly modifying the lift kit is next and the muddies.

Cheers Pete

Pete, I moved your tyre question to here.

Because it's not Mitsubishi specific it doesn't need to be here, and you'll reach a wider audience in General Tech.