Thread: P38 what size tyres fit

Hi Jase

A guy in our club and on this forum - Steinzy - runs 265/75R16 Cooper STT's on his P38 and he has also had his computer reprogrammed so it rides higher than standard on the airbags - looks good. Whilst getting it reprogrammed through Autologic, he had a few other things changed too as I beleive the computer is the same in all models and LR simply enable certain things for different models - one touch windows etc.

Hope this helps, but yes Hardy is the other P38 guru plus I beleive P38Rover on the forum should also be able to help..........wouldn't have guessed by his name eh?

Aye, Mick

Hi Jase, I have the same size tyres on my p38 as Steinzy and I think Hardy. Mine are on 18" though, but overall they are just larger than 32" tyres. They rub when turning on highway mode and when over bumps etc. A slight lift of 1-2" will clear that up. I have removed the front mud flaps aswell as they definately rub there. 31"'s should be ok but it will be close. Plus the p38 looks heaps cooler with some rubber on it.

Gearing is still fine I have the 4.6 so it still goes well. Definately slower at times but ticks along nicely at 100 kph. he fuel economy has suffered with me from around 20L/100k's to about 22. Off road the tyres are awsome cooper 275/65 18's but on road are a little less grippy in the wet. In the dry they are pretty good. Braking takes a little more pressure but this is not a major issue.

Hope this helps.

Charlie

Jase

What does a "diff radio" do? Is there some new type of two speed diff I should know about?

Originally Posted by jase

........................... by far cheaper than diff radio swap)
....................

Thanks
jase

I haff nevre mafe a tupogfical mithake meself! Bt tat's bcause "m carfull B4 me posts!

Diana

I also run 265/75R16 Cooper ST tyres. The spare won't fit into the wheel well hence the spare wheel carrier on mine.

Grip in the wet is not as good as the Michelin XPC and they are certainly noisier.

They do foul the front mudflaps at full lock when in Access Mode. They also foul the rear wheel well liners when the suspension bottoms out when the EAS has failed and lowered the car to the bumpstops (as I found on my recent trip from Kempsey to Sydney)

Ron

Umm thanks
should read ratios not radios (fixed now, obviously let my typing prowess and knowledge of the english language out of the bag )
I was referring to having to change crown wheel & pinion to reduce hwy RPM's
(not even sure if what would be avail but if it was I probably couldn't afford it)
Jase

Originally Posted by Lotz-A-Landies

Jase

What does a "diff radio" do? Is there some new type of two speed diff I should know about?



I haff nevre mafe a tupogfical mithake meself! Bt tat's bcause "m carfull B4 me posts!

Diana

Jase,

One mistake I made was not putting on the biggest possible tyres - especially way back when I had the money. I bought 265/75 (32") but should have gone 255/85 or 285/75 (both 33") which I now can't really afford....

Anyway - say you just want the biggest that will fit without mods - then 255/70 is the go. 245/75 is cool too, but they may rub just a little on the front flaps.

265/75 is about the biggest you'd want to go without mechanical mods. An EAS reprogram will allow you to live & drive with these tyres no probs - EXCEPT for when the EAS goes out to lunch. Boink - onto the bumstops but guess what? Any size bigger won't be able to roll because the cars body work is resting on them. Bit of a problem that.

So any bigger and you'd want a spacer lift - one that includes a bumpstop change - basically for reasons associated with the tyres rubbing.

And regarding diff ratios, the standard 3.54's will cope with sizes up to 32" - a difference you'll really notice. Any bigger and it would be pretty horrible - not just degraded acceleration but steep dowhill runs in the bush. The Auto would just want to run away.

The next step up is 4.10 Crown Wheel & Pinion but only one mob make these at the moment - Great Basin Rovers in the States. I'm running these in mine, hence the regret in not going with 33"s or bigger.
Maxi Drive used to convert 4.11's from RR Classics to fit into P38a but it cost an enormous amount of money.

I've got my other set of 4.10's on eBay at this very moment...


Hope this helps,
Hardy

Thanks Hardy
that's exactly the info I wanted to know
I actually want to raise my gearing a bit, hence the bigger tyres
after having the HS2.8 in my fender for a little while I have realized I need to get it spinning slower at 110km/h to get some better fuel economy,
Yes the conversion is still ongoing, getting the adaptor plate made has taken forever, mean while the wife's been spending a lot of time driving the ute (her P38 has been without an engine for 12 weeks now ) and is not very happy with me , (I was tempted to put the V8 back in while waiting for bits but too much work)
Anyway the HS2.8 has more torque than a tractor (max torque 1400 rpm) so holding hwy speed at 1800-2000rpm should be no probs (certainly isn't with the manual g'box in the fender) and spinning it that bit slower will hopefully improve my fuel economy
anyway thanks again
Jase

HS2.8 into P38 - cool. 'Be a good car then!

"One day I'd like to bolt 2x TD5's together and make a U10, then chip 'em"

So are you keeping the ZF?
Shame there's no viable 6spd option available.


Hardy