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

Submitted: Thursday, Jun 05, 2003 at 11:42
ThreadID: 5299 Views:2255 Replies:8 FollowUps:14
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I'm after some specific feedback on the 265/75/16 tyres on the GU 3.0td.

I have the 'off the shelf' 265/70/16's and am tossing up the pro's and con's of going to the 75's

The info I am specifically looking for from those currently running 75's is
1. Any increase/decrease in fuel consumption?(most important)
2. Have they effected power on take off?
3. Is there more brake pedal pressure required to stop the car?
4. Any other comments you have?

Thanks in advance to all.
Andy
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Reply By: Andrew - Thursday, Jun 05, 2003 at 11:45

Thursday, Jun 05, 2003 at 11:45
Sorry people...

Also, are you running a manual or Auto????
AnswerID: 21907

Reply By: Member - Rohan K - Thursday, Jun 05, 2003 at 12:41

Thursday, Jun 05, 2003 at 12:41
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)
AnswerID: 21912

Reply By: Pete G - Thursday, Jun 05, 2003 at 13:03

Thursday, Jun 05, 2003 at 13:03
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

AnswerID: 21914

Follow Up By: Pete G - Thursday, Jun 05, 2003 at 13:09

Thursday, Jun 05, 2003 at 13:09
Further to the reply previous to mineno engineers certificate is necessary in the case of the nissan as long as you fit the alternative tyre size sticker. This is because the manufacturer has allowed the alternative tyre size to be used (on another vehicle in the range).

If the sticker were not available then an engineers certificate would be required.

Regards

PeteG
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FollowupID: 14331

Follow Up By: Member - Rohan K - Thursday, Jun 05, 2003 at 13:29

Thursday, Jun 05, 2003 at 13:29
Peter G, is that because the 265/75-16 are run on the cab-chasis model?Life just ain't that serious.
Rohan (Sydney)
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FollowupID: 14333

Follow Up By: Member - Rohan K - Thursday, Jun 05, 2003 at 13:31

Thursday, Jun 05, 2003 at 13:31
If so, that means under the regulations, you could go to a 275/75-16, as you are permitted 15 mm above what's indicated on the tyre placard sticker.Life just ain't that serious.
Rohan (Sydney)
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FollowupID: 14334

Follow Up By: Pete G - Thursday, Jun 05, 2003 at 18:01

Thursday, Jun 05, 2003 at 18:01
Folks: apologies for some clumsy typing.

The 70 profile tyres from bridgestone are a "passenger radial" type construction. In the first para the 2nd sentence should read 265/70/16's

The 75 profile tyres have a much stronger sidewall. If you reference the Bridgestone site the 265/75R16 LT's in Dueller D693's come with a lot of added strength features compared to some other sizes in that range of theirs.

In Followup No. 1 mineno should read as 2 words.

Basically to depart from the placarded tyre sizes you need either a revised placard (sticker) from the manufacturer or if this is not available then an engineers certificate.

The RTA regs apply relative to the largest tyre listed on the placard
(ie 15mm dia and xxmm wider etc)

Regards

PeteG

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FollowupID: 14368

Follow Up By: Member - Rohan K - Thursday, Jun 05, 2003 at 19:56

Thursday, Jun 05, 2003 at 19:56
Thanks Peter. That's as i understand it too. The xx above, is 26 mm in NSW.Talk is cheap ...
Rohan (Sydney)
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FollowupID: 14379

Reply By: tristjo - Thursday, Jun 05, 2003 at 13:41

Thursday, Jun 05, 2003 at 13:41
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.)
AnswerID: 21919

Follow Up By: Member - Bill- Thursday, Jun 05, 2003 at 16:47

Thursday, Jun 05, 2003 at 16:47
Tristjo,

I think the new petrol wagons run 275/70 like the tojo's.

As for the original question, I just put 265/75LT's on my new 3.0Di Auto. No economy figures yet, but it's sure to be no worse on the highway. It does feel a little more suggish up steepish hills, but from take-off it's not real different. I think the Auto probably takes up the slack. Definitely more pedal pressure to stop but not a big deal.Regds

Bill
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FollowupID: 14361

Reply By: Pete G - Thursday, Jun 05, 2003 at 13:50

Thursday, Jun 05, 2003 at 13:50
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.

AnswerID: 21921

Follow Up By: Member - Rohan K - Thursday, Jun 05, 2003 at 15:50

Thursday, Jun 05, 2003 at 15:50
Thanks Peter. That's also how I "read" it. The 275/75-16 is exactly 15 mm larger in diameter than the 265/75-16 so I assume it's OK.

Not that any of this helps me - I own a Pathfinder and unless I can convince them that the 285/70-17 used on the US Pathfinder Amarda (yet to be released), is an eligible alternative size, I don't have much option in tyre sizes. Back to the engineer, I guess.Life just ain't that serious.
Rohan (Sydney)
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FollowupID: 14348

Follow Up By: Pete G - Thursday, Jun 05, 2003 at 17:46

Thursday, Jun 05, 2003 at 17:46
Rohan,
In your case you need either an approved tyre placard from the manufacturer or an Engineers Certificate if the placard is unavailable.

In the case of the GU ST Patrol to upgrade to 265/75R16 LT's all you need to do is to purchase the sticker from Nissan (about $8.00).

Regards

PeteG
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FollowupID: 14364

Follow Up By: Member - Rohan K - Thursday, Jun 05, 2003 at 19:51

Thursday, Jun 05, 2003 at 19:51
Thanks peter. I've spoken with Nissan and have been told there is no alternate size for the Pathfinder, so if I want to up the size, I'll need a engineer's cert.Talk is cheap ...
Rohan (Sydney)
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FollowupID: 14377

Reply By: GUPatrol - Thursday, Jun 05, 2003 at 17:34

Thursday, Jun 05, 2003 at 17:34
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
AnswerID: 21935

Reply By: sean - Thursday, Jun 05, 2003 at 21:20

Thursday, Jun 05, 2003 at 21:20
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

AnswerID: 21958

Follow Up By: Andrew - Thursday, Jun 05, 2003 at 21:29

Thursday, Jun 05, 2003 at 21:29
Thanks Sean, you are one of a few who actually answered the question. Not that I'm complaining, I need all the help I can get.

Your 2000 model, manual I guess???

And what ecomony figures are you actually getting, if you know??
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FollowupID: 14389

Follow Up By: sean - Friday, Jun 06, 2003 at 10:27

Friday, Jun 06, 2003 at 10:27
I run a roof rack also and get mostly 7.2 km/l at 100 to 110km/k (say 14l/100ks) average highway. Remove rack and 7.5 to 8.2 litres per 100km.

Car is manual.

PS - If you have a 3 litre make sure you check oil level correctly and then always check it on long runs between the 10,000 km services.

Cheers

Sean
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FollowupID: 14407

Follow Up By: Member -BJ (Sydney) - Friday, Jun 06, 2003 at 16:02

Friday, Jun 06, 2003 at 16:02
Sean, if you haven't changed your brake fluid yet do it as i just did mine as recomended after 3 years & it improved brakeing heaps, same model as you but auto.Regards Bob
3 Weeks till Gulf trip
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FollowupID: 14429

Follow Up By: sean - Friday, Jun 06, 2003 at 16:12

Friday, Jun 06, 2003 at 16:12
Bob

thanks for that.

Enjoy and make sure you Keep us posted on your gulf trip you lucky B*****d.

Sean
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FollowupID: 14430

Reply By: Andrew - Thursday, Jun 05, 2003 at 21:23

Thursday, Jun 05, 2003 at 21:23
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.?????
AnswerID: 21959

Follow Up By: Goodsy - Saturday, Jun 07, 2003 at 01:48

Saturday, Jun 07, 2003 at 01:48
Same as in Vic but you will need an engineers with the larger tyres. Insurance is concerned about rim size aparently because "cars" with larger rims are more likely to be stolen. Tyre size is a roadworthy thing. Larger tyres no road worthy no insurance if they can say the tyres caused the accident.
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FollowupID: 14457

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