Specific Question For GU 3.0TD owners running 265/75/16's tyres

Sorry people...

Also, are you running a manual or Auto????

Andrew, the 265/75-16 is 27 mm larger in diameter than the OEM tyre and is therefore technically illegal in some states like NSW (unless you get an engineer's certificate).

Fuel economy will be determined by many things, much of it up to you, such as the load you place on the motor. For example, as acceleration will be slightly slower, if you push the gas pedal harder to make up the difference, you'll use more gas. However, at cruising revs and speeds, you should achieve better economy.

The increase in circumference is about 3.5% so you could expect a slight negative impact to acceleration (not sure you'd notice it) and a reduction in revs for any given speed (of approx 3.5%).

With larger diameter tyres, there is less engine breaking effect so, yes, more brake pedal pressure is required. However, with a relatively small increase like 3.5%, I'm not sure you'd notice much difference, if any.Life just ain't that serious.
Rohan (Sydney)

Andrew,
I have done this with Bridgestone AT's - same as fitted to the Utes. That way you get a stronger sidewall cf the passenger vesion AT. (265/75R16 LT's (D693's)). Note that these are different to 265/75/16's which are a "passenger radial".

There is a small increase in diameter of about 24mm which equates to about 3kph at 100kph - in fact this reduces the over-read of the speedo from 6-7 km to 3-4km.)

Personally the only -ve is a slightly harsher ride. No noticeable differences in other factors ie power, braking or fuel economy. This is with a manual. I run 36-38 Psi on road. So far 50k's and looking like they will do another 20-25k's easily.

To make things leagal you need to get a sticker for the alternative tyre size from Nissan and stick on the tyre placard (The part No was posted on this forum a few months ago) . In NSW this is necessary for an increase of more than 15mm in diameter.

If you have been watching this site previous posts refer to issues with Coopers and BFG's.

Yes it is somewhat confusing - you also need to consider the speed and load ratings specified on the vehicle tyre placard (for ST Patrol this is 112S) the 112 is load rating which is minimum the S is the speed rating which is allowed to be as low as N (any lower requires a label to be affixed to Windscreen)).

For further info refer to RTA and Bridgestone websites.

Regards

PeteG

If you are in QLD,

The law states that you are able to use a tyre that is up to 50mm larger in diameter than the largest factory fitted tyre for that particular model.

Example: (I beleive this is how it works)

In a GU Series 3 patrol, the largest tyre fitted is on the 4.8ltr. It runs 265/75/R16's This size has an rolling diameter of approx 810mm. Therfore you could run a 34inch tyre legally, as long as all the other conditions were met.

There is no doubt about it, changing sizes can be a nightmare, but IMHO, it is well and truly worth the trouble. The difference can be quite amazing, and anyway, you've gotta love shopping for new rubber!! Don't ya just love the smell!!

Tristjo.

(oh, and by the way, if any of my info is incorrect, please let me know. Thanks.)

Rohan,

The 265/75R16 LT's are standard on the Ute (Cab Chassis).

The RTA website - vehicle standards has a data sheet on this issue. The 275's would be a larger dia than the 265's given as the sidewall height is a function of the width.

In NSW it is permitted to fit tyres that are less than 15mm larger diameter and (25mm I think) in width than the largest listed on the Tyre Placard. Hence if a 265/75 is permitted (as per the new sticker applied) then as long as dia is not more than 15mm more then this would b e OK.

Also refer to the Bridgestone website.

No engineers certificate required, Nissan Supplies the sticker (genuine NIssan part) to replace the original with when you do this change.
I got one in mine.
We aware that the cab chassis are 4.2TD engines and so is mine, I cannot comment on the other aspects of the 3.0L performance, just on the compliance of that change.

Will

Nissan 3 litre 2000 66,000kms.

I have 265/75/16 BFG AT with are new and they replaced set of same.

Economy - reduced. I never get the figures quoted by some and I got better economy with tyres that came with car. Guess (note guesss) is 1 litre/100km increase in consumption due to lugs.

Acceleration. No difference noted. Power is never a problem.

Take off no probs - not even a consideration.

Brake pedal - 2000 model does not have best of brakes to start with.

Speedo. At 100km/h indicated GPS has it at less than 0.5km/h error.
50km run on dead straight had odo at 50km and GPS at 50km so error is very little with these tyres. Old and new tyres made very little difference to these figures.

Hope this helps some.

Sean

I'm in WA. Spoke to my insurance Co (SGIO) and asked them about going to the 75's

I spoke to a guy in their resolution section who said over here we can only put up to an 8inch rim on the GU, which it has standard anyway, and you can put what ever size tyre on the rim you want, as long as it is rated for the particular rim you have. Overall diameter etc doesn't matter (he said)

He said he had noted it in my file that I intended to go to 265/75's and there is no issue with that.

Any one had any probs in WA contrary to this.?????