Tire sizes and performance / speed

[Krippel6]

Hi guys,

I have a 99 4.2 GL Wagon, when I bought it, it had 245/70(could be something else)/16s on.

Stock is what 265/70/16? and I see a lot of discussions on here about going to as big as 285s. One of the main issues that I've got with my car at the moment is that I have to do like 140 on the speedo, to do 120 on the GPS. Which I don't like to do, cuz the NA diesel sounds like it wants to take off

If I put on bigger wheels, it will obviously make the speedo more accurate, which will mean revs/km will be lower too. So I can cruise a real 120/125.

My question is - not that we measure 0-100 in seconds on these vehicles - but what is the impact on performance? Will it be _that_ noticeable?

Anyone done this sort of thing before - specifically on the NA diesels, as in, went from a pretty small wheel (smaller than stock) to bigger than stock?

Thanks!

[Tinus lotz]

All round the 33 works good on 4.5 4.8 4.2 and 30l my friend christo boegman has a set of 305 70 16 on his 4.2. Pick up and just asked him now he is happy with it makes the speedo spot on a little slower on the pull away but better on the high way says he does about 2800 rpm at 120km he also loads very heavy and no problems
I would go for 285 75 16 witch is also a 33 inch
Auto wiel had some MTR s for about 2000 a pop can find out if they still have stock. ?

[Krippel6]

Thanks for the response man.

I can't really afford to spend 8-10k on new tires at this time of year :P

So will be shopping around (read: will probably do it in Dec around bonus time)

[Peter Connan]

Krippel6, I believe Tinus answered on the basis that you have a Petrol engine, while I suspect from the date of manufacture that you have a diesel?

May I suggest you PM Russ Kellerman, he has a N/A Y61 pickup with larger tires on.

There is definately a significant impact on performance with 285/75 R16's on that engine and you will notice that you have to gear down far more often, but on the other hand off-road performance is also improved under many different conditions and many of us feel that the overall result is better. That is however a matter of personal preferance.

[Tinus lotz]

I agree speak to russ or contact christo on o836five3610nine he has it on his diesel bakkie , he also has a nother patol bakkie with standarrd tires so between the two of them you will get the best info

[AndriesS]

On my 4.8GL , the 285 gave me a speedo error of 0, driving 120km/h on the speedo is 120 on GPS.

That said, the vehicle feels a bit lazy which but once you get going nothing stops you.

[ricster]

I have a 4.2 diesel.... but mine is turbo'ed, so there will be a slight difference in performance between our Patrols. Firstly, 33" or 285's will work on your Patrol. Your pull off will be slightly more sluggish, but probably hardly noticeable. where you will feel it though is on an uphill.

Secondly all of the above is also affected by the type of 33" tyre you fit. Should you fit highway tyres the above issues will be minimal and again, hardly noticable. All terrains will be a bit worse, but still ok. But fit 33" muddies on and the power does disappear quite a bit, especially on a N/A 4.2. This also does affect the turbo'ed versions quite a bit, by causing the EGT's to climb rather quickly, to compensate for the power drain. But hey ... a big Patrol needs big shoes !!

I fitted Kumho 33" Muddies, and now that they are just over half way worn, my speedo is now out by 4km/h, but was spot on when new. At present at 120Km/h I am at 2600 rpm.

in my opinion ..... go for the 33's !!!!!!.... just chose the tyre for what application you will be using the Patrol for.

Maybe if you know someone in your area with a set of 33", see if you can swap tyres for a few Km and see what they feel like. I'm in Alberton area, and have no problem meeting you one Saturday and swapping tyres for you to try.

[Krippel6]

Hey - Thanks Ricster.

That might not be a bad plan, my "skoon famielie" live out that way, I can go drop the wife and kid, and pull in for a quick test (heh... how quick is it to change 4 wheels hahaha)

But yeah, thanks man. I'll PM you when next I'm going that way :)

[ricster]

Cool ... I'll PM you my number. Give me a call when you are ready.

[Traveler]

I have 265/75R16's fitted which is one size up from the standard 265/70R16's that was fitted by Nissan. (Granted mine is 3.0 GL)

When doing 120km/h on the speedo, I am 120km/h on the GPS (Nuvi and Montana).

I really wanted 285's, but then Repulse would not have fitted into the garage.

Groot skoene is mooi.