tyres

Submitted: Wednesday, Aug 10, 2016 at 11:17
ThreadID: 133188 Views:4246 Replies:13 FollowUps:6
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I have no doubt this has been discussed before but, I cannot find a thread on it,and this is a bit of a delema for me, I bought a Nissan patrol GU 2000 and it looks like it may have done some off road work,lift kit etc but,the previous owner put oversized tyres on it, that a tyre shop tells me are illegal for this car, also the police are having a field day with my speed,as it is 10km/h faster than on the clock, the tyres in question are Goodrich all terrain t/a 285 75 16 I have 4 on the vehicle that have about 40% tread left and 2 brand new tyres never used.
I have been advised to go down to 265 70 16 to bring the speedo back into sync, also a 4wd chap said he bought Sailun teramax tyres and swears by them.
Could I please get comments and advise on the above,
Thanks,
Ian.
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Reply By: Member - nick b - Wednesday, Aug 10, 2016 at 13:12

Wednesday, Aug 10, 2016 at 13:12
Ian , you should be able to get the larger type approved for your car & have the speedo drive changed the read correctly......
Cheers Nick b

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AnswerID: 603265

Reply By: Member - Roachie - Wednesday, Aug 10, 2016 at 14:44

Wednesday, Aug 10, 2016 at 14:44
If you're not planning to use the vehicle for serious off-road driving, I'd be inclined to start working towards a new set of 265/70R16....or better yet, 265/75R16 (which are much more common and would still be within the legal size, being only slightly larger than the 265/70R16s.

You should have no trouble selling the 2 brand new tyres (on this forum, or Gumtree etc) and by the sounds of it, you wouldn't need the second spare ....again, that is assuming you aren't doing any serious off-roading or remote/outback travel etc.

The smaller tyre size will give you enhanced fuel economy AND make the vehicle better able to handle standing starts (due to the gearing change).

As has been said already, you MAY be able to get the vehicle "engineered" to run the larger tyres (expensive to get approved) and you MAY be able to source a new speedo gearing gizmo from the likes of Mark's Adaptors which would alter the speedo so that it reads correctly for the larger tyres....but why would you bother unless you really NEED the bigger rubber?

Good luck,

Roachie
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AnswerID: 603267

Reply By: Robin Miller - Wednesday, Aug 10, 2016 at 16:24

Wednesday, Aug 10, 2016 at 16:24
Hi Ian

You need to say your Patrol model and location as these may affect the answer.

The patrol GU series speedo reads correctly with 33 inch tyres (285/75/16) this is because from new the speedo was made to read 100 when you are actually doing 94 with the 265/70 tyres.
The approx. 6% increase with 33's then make it read right.
Off course the car is 16 years old and may have mods done.
Check against gps navigator .

285/75/16 is right on the margin of being legal, (all my patrols are).

Mostly throughout Aussie land we are going to 2" lift and 1" tyre lift making max of 3" total.

Now the issue is what is a 1" tyre lift - many refer to 1" above placard but this is not necessarily correct.

In Victoria the ruling relates to tyre being larger than any tyre fitted to that model car and this is allowed to be 15mm diameter, now if you look in the cars handbook you will note than one model is fitted with large 245/85/16 tyres.

285/75/16 is within that limit.

There is a lot more about this than my brief comment search for ->

VSInumber8Guidetomodificationsformotorvehicles.pdf


Agree with other comments saying 265/75/16 or 32's about a good general size , 33's though for bush.
Robin Miller

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AnswerID: 603269

Reply By: swampy - Wednesday, Aug 10, 2016 at 18:52

Wednesday, Aug 10, 2016 at 18:52
hi
First
Smaller or larger tyres can have a positive or negative effect on
fuel economy
power at a particular rpm
can put additional strain on engine if over geared [to larger tyre]

First the rule of tyre size used to be 3% variation in diameter
Currently there seems to be different rules for different states .
Legally as long as its approved in one state of Australia its legal everywhere .
This is a slight grey area because every cop has a different opinion and suddenly they are engineers and mechanics . THEY ARE NEITHER .
Due to our wonderful legal system and a Road transport that out right sucks this is also a hurdle . You maybe correct in every way but you have to prove it in court .
This has been discussed at huge length on this or another site . It also included the quoted legal requirements .

Anyways if tyres of differing sizes are offered as an option it first is best to have the appropriate diff ratio and speedo drive specified for that option .

swamp
AnswerID: 603273

Reply By: Member - Ian C26 - Wednesday, Aug 10, 2016 at 19:20

Wednesday, Aug 10, 2016 at 19:20
Thanks everyone with your answers, I had heard about the gearing change and the cost, not a road I think I will go down.
I had been told by a tyre company in Geraldton that the Patrols came out with a smaller tyre off the line, but, they weren't considered safe or something and began putting bigger tyres on them, I don`t know how true that is, but the 70 & 75 ring a bell in that area but I would imagine the difference between the two would be negligible wouldn't it?
Has anyone had any experience on the new tyre brand I`ve been suggested to buy...Sailun Teramax.
Regards,
Ian.
AnswerID: 603277

Follow Up By: Rojac - Wednesday, Aug 10, 2016 at 21:48

Wednesday, Aug 10, 2016 at 21:48
What cost per tyre?
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FollowupID: 872924

Follow Up By: Member - Ian C26 - Wednesday, Aug 10, 2016 at 21:57

Wednesday, Aug 10, 2016 at 21:57
$ 199.00 they are sold down in Rockingham W.A I believe they have outlets in Qld, N.S.W Vic S.A & W.A
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FollowupID: 872925

Follow Up By: 08crd - Wednesday, Aug 10, 2016 at 22:12

Wednesday, Aug 10, 2016 at 22:12
I've had a great run from Hankook RF10 all terrain tyres.
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FollowupID: 872926

Follow Up By: Rojac - Thursday, Aug 11, 2016 at 09:15

Thursday, Aug 11, 2016 at 09:15
Prior to getting my last set which were Mickeys ATZ P3 ( $300/t) I was looking at Federals for $245.

Never heard of that particular tyre, but not overally cheap for $199/t
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FollowupID: 872930

Reply By: CSeaJay - Thursday, Aug 11, 2016 at 11:59

Thursday, Aug 11, 2016 at 11:59
Good replies so far.
Remember also that going back to the correct sized tyre will be kinder on your brakes. It is not just acceleration and rpm to consider.
CJ
AnswerID: 603288

Follow Up By: Member - Ian C26 - Thursday, Aug 11, 2016 at 16:21

Thursday, Aug 11, 2016 at 16:21
Thanks CJ, I think that is the way I will go 265 70 16 I have checked on the placard in the glovebox and this is the tyre that is recommended, I presume with these tyres you could still go 4wding couldn't you? I look forward to seeing the improved fuel economy & the money saved.
Regards,
Ian
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FollowupID: 872939

Reply By: Baz - The Landy - Thursday, Aug 11, 2016 at 16:54

Thursday, Aug 11, 2016 at 16:54
Ian

I use the following and have found they work well for me and have been across numerous terrain, including off-track desert work...

. Toyo M55 265/75/16R

Good luck on your deliberations...Baz, The Landy
AnswerID: 603304

Reply By: swampy - Thursday, Aug 11, 2016 at 18:06

Thursday, Aug 11, 2016 at 18:06
hi
Ian26
Going both big and small in tyre diameter can have a negative effect on fuel economy . It can depend on how the vehicle was geared to start with .
Engine tune etc
Conditions of use offroad or tarmac .
Very generally speaking fuel economy will improve with lower revs but put a van on /go offroad and it may be more than terrible .
It all depends upon circumstance .
Donot mix up really bad first gears either ,some are so low use 2nd to start off from the lights . Some are geared so high ,the vehicle has little lugging ability [ u cannot pull very very heavy loads at slow speed ].

swamp
AnswerID: 603309

Reply By: McLaren3030 - Sunday, Aug 14, 2016 at 15:34

Sunday, Aug 14, 2016 at 15:34
As a rule of thumb, one size up from standard generally will not cause an issue with regard to the law, or your speedo. In most cases, the speedo tends to read slightly, (3 to 5) kms below actual. Going one size greater tends to put the speedo closer to actual. Having said that, every car is different, my wife's Corolla read 8 kms below actual, & my 76 series land cruiser read 5 kms below actual. I went from 265/70 R 16's to 265/75 R 16's, and brought my speedo up to actual.

I use Cooper ST Maxx, and have found them to be a good all round tyre, not too noisy on bitumen, but with an aggressive enough tread for the rough stuff.

Macca.
Macca.

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AnswerID: 603386

Follow Up By: Member - Ian C26 - Sunday, Aug 14, 2016 at 16:06

Sunday, Aug 14, 2016 at 16:06
Thanks Macca, sounds good but, how will I know whether the 70 or 75 is the one to bring the speedo back to the correct reading, the placard in the vehicle says 70.
Ian.
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FollowupID: 873015

Reply By: McLaren3030 - Sunday, Aug 14, 2016 at 16:21

Sunday, Aug 14, 2016 at 16:21
The placard on my vehicle also reads 70. It is really a matter of trial & error. As I said, every car is different.
Macca.

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AnswerID: 603390

Reply By: Malcom M - Monday, Aug 15, 2016 at 12:23

Monday, Aug 15, 2016 at 12:23
Aside from anything mentioned above, flares can easily be fitted to the wheel arches to make the tire size legal.
Lots of people make speed correction boxes which simply connect to output of the transfer case electronics. I use an Australian 'Yellow Box" which has been simply brilliant.

There is both good and bad reasons for having large wheels fitted such as ground clearance. You need to provide more info on what you will be doing with the truck...
AnswerID: 603416

Reply By: Batt's - Tuesday, Aug 16, 2016 at 13:51

Tuesday, Aug 16, 2016 at 13:51
If the tyres are no more than 50mm taller overall than the tyres that model of vehicle came with than they are legal in Australia. I don't know about legalities of your speedo but if you're happy with the tyres there are devices that can correct the speedo.
AnswerID: 603443

Reply By: LAZYLUX16 - Thursday, Aug 18, 2016 at 07:48

Thursday, Aug 18, 2016 at 07:48
I have set of Kelly Safaris .Not big brand in Oz but huge in USA .Priced reasonably at $290 .So far doin great and no chipping on rocky tracks and forgot to let them down on one track ..
AnswerID: 603483

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