GU std tyres & speedo reading

all new cars speedos read more than what your doing...

265/75/16 fix the prob
285/75/16 do really well on them

Hi Jed
Two things stand out here. First I always take it as my responsibility to check what I am buying and how it works/performs etc. Don't always trust what some other guy tells you, unless he is an expert in his field. Try standing in front of the judge saying "I assumed ....." or "I thought...... "
However if you bought vehicle/tires brand new and got caught for speeding when you believed you were not speeding, get an independant "expert" speed /tire witness to verify your argument and you may just be able to convince the judge that your "intention" was not to speed that it was a fact of someone else suppling you with a product that was at fault.
If you still sustain a conviction and feel strongly about it see your friendly solicitor and hold the supplier at fault. Sue, sue ,sue.
I find it easier to use my GPS, check my speedo and make due allowance. Its a lot easier than trying to find the right sized tyre. My Pathie speedo used to show 110kph when actual speed was 107kph. Perfect ffor not getting caught.
Cocka

Jed

I assume you have the 3.0TD

I have the same standard tyres withe same problem. It is a known fact.

265/75/16 fix the problem pretty much spot on I am lead to believe. (I haven't done it yet, just waiting for old ones to wear out).

Be carefull about fitting anything larger IMO. Previous questions re this sort of thing in the forum indicate a power loss and petrol increase with tyres too big. Something to do with the engine management system, the engine pushing more rubber and weight etc.

Depends what you want the car for, if you want height and off road performance bigger tyres may be for you. If your just a MR normal, use it now and then guy, I'd just go with the 265/75's

cheers

I think the reason is because the GU Patrol in its various guises comes in 3 different tyre sizes. The DX diesels are 7.50R16, the ST diesels are 265/70R16 and the ST & TI petrol are 275/70R16.

Nissan has probably set up the speed to be spot on with the largest tyre, the 275/70R16. Hence with the 265/70, the speedo will overstate the speed to some degree. However, it should be only a 2% variation if you go purely by tyre size.

GU Manual ST with original tyres on one particular trip was dead on 1000km's.
I changed to 257/75/16 BFG and the same trip became 960 km. 40 km differerence or 4%.

I went under the speedo check west of Melb. and at 80km/h speedo read 79-80.

Hope this helps.

Sena

All

Many thanks for all the above tyre size/speedo advice.

I will first check with the friendly Nissan Australia Support people to see if they have some speedo error figures for different tyre sizes for my GU 3.0TD & see if there are any consumption/warranty implications or ACT transport rules (15mm max I think) that might limit my final choice in new tyres.

Looks like 265/75/16 seems to be the popular choice for normal needs.

Cheers