Maximum Tyre Size on P38 on 18" rims

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DM68 said:
.

I currently have a set of 255/50/19 tyres on my p38.

Now the question is can i put some 265/65/18 tyres onto it. I know your supposed to only increase your size by +/-2.5% but fitment of these tyres would increase it by 8.67%.

So has anyone fitted this size tyre and if so,is there any adverse effects or not.
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This was the initial question asked, which 2 years ago clearly states a genuine query and yes i knew the pros and cons but it was the adverse effects on handling,body rubbing and general fitment i was interested in. So how can this be construed as a bit silly. At the time i didn't know any better, but after fitment of the wheels and tyres i now do know. Its only through starting threads like this that members learn from other members the pros and cons of owning these cars. I was always taught if you dont know ask the question,so if you think it was a silly question, fair enough,but the way i view it is, the early responses i got could have saved me a fortune.
 
DM68 said:
This was the initial question asked, which 2 years ago clearly states a genuine query and yes i knew the pros and cons but it was the adverse effects on handling,body rubbing and general fitment i was interested in. So how can this be construed as a bit silly. At the time i didn't know any better, but after fitment of the wheels and tyres i now do know. Its only through starting threads like this that members learn from other members the pros and cons of owning these cars. I was always taught if you dont know ask the question,so if you think it was a silly question, fair enough,but the way i view it is, the early responses i got could have saved me a fortune.
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OK sorry did not see the date on first post. Must pay more attention. :)
 
P38, still on air, standard dunlop suspension-airbags. So no lift:

Maximum tireheight on a non lifted P38 is 32”. All following tires are about 32”

235/85R16 works excellent;

265/75R16 to wide, eats front fenders in offroad conditions;

245/75R17 works excellent;

265/70R17 to wide eats front fenders in Offroad conditions;

255/70R18 the widest and tallest tire you can fit on a non lifted P38 without the tires touching anything. I tried all of the above sizes in Mud- or/and Simex-profile tires.

Yes, people told that 265/75r16 will work, I bought a set Simex (for the more heavy offroad) and a set of 265/70R17 Coopers for everyday use and milder offroading. Costed me, well not cheap, only to see them eat my fenders. Dont’t believe it, 265 is to wide on a non lifted P38, if used offroad.
Also keep in mind that for 32” tires the exhaust needs to be adapted (the tires hit the rearmufflers under compression)
 
The definitive answer to this long drawn out thread is that any tyre with a larger rolling radius than those fitted from the factory, renders the vehicle illegal to drive on the road.
 
wammers said:
The definitive answer to this long drawn out thread is that any tyre with a larger rolling radius than those fitted from the factory, renders the vehicle illegal to drive on the road.
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Is that due to speedo being wrong? What if you had the speedo re-calibrated?
It used to be common years ago to put 7.50s on swb for the bigger radius
 
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This probably wouldn't work then?
 
kermit_rr said:
Is that due to speedo being wrong? What if you had the speedo re-calibrated?
It used to be common years ago to put 7.50s on swb for the bigger radius
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Think you will find Land rover supplied differing speedo drive components to change drive ratio on early models. We are talking a P38. Up to 2001 in the UK actual speed could be plus or minus 10% at an indicated 30 MPH. So at an indicated 30 MPH the actual speed could be between 27 and 33 MPH. This 10% rule was applied to all speed limits. Hence vehicles made before 2001 could travel at 77 MPH on a motorway and not be speeding. And pro rata for all other limits.Thanks to an EU rule brought in in 1999, actual speed could be 10% lower than indicated but never faster than indicated. This came into force in the UK in 2001. Any vehicle made in or after 2001 has to comply with the new regulation. In other words a vehicles speed can be 10% lower than indicated, but never higher. Vehicles made before 2001 can still use the plus or minus 10%. That is why speed cameras are set plus 10% plus 2 MPH for each speed restriction before they go off. People driving a vehicle made before 2001 cannot be done for up to 10% above the speed limit by the stupid jobsworth detector vans and radar gun operators who seem to think 31 in a 30 area is dangerous. But as said by someone famous "Not a lot of people know that". So if your new tyres put the speedo out more than 10% in any vehicle the car is illegal. Larger tyres give a faster actual than indicated speed.
 
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