Tyre sizes
Submitted: Wednesday, Mar 31, 2004 at 09:49
ThreadID:
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Bob et Joëlle
Hi all
I know this subject has been covered many times and I have looked at all the threads that I could but I have a specific question.
Our LC 100 TD came with Dunlop Grand
Treks. Tyre placard says 275/70R16 which is what they are. We want to do a trip to the centre later this year and plan to do a
suspension upgrade and get new tyres before we go.
After a lot of research (including here) and talking to people the choice for tyres came down to BFG A/T or Coopers ST. We inclined slightly to the Coopers. From the Coopers web site it appears as though they do not supply our size - the closest is 285/75R16. BFG have both. I know there are arguments for and against going up a tyre size and we have not finally come to a view about that - BUT the real question is - could we put the Coopers on and be legal in NSW.
Thanks for any input.
Bob & Joëlle
Reply By: Baz (NSW) - Wednesday, Mar 31, 2004 at 10:32
Wednesday, Mar 31, 2004 at 10:32
Hey Bob i would go the BFG's, stay with the same size you have, save's getting the speedo adjusted, not much difference but maybe enough to get booked for speeding, and they are both very good tyres, IMHO.
Baz.
ps, I have BFG A/Ts 55,000ks 25,000 off road not a prob not even a flat, touch wood.
AnswerID:
52621
Follow Up By: Bob et Joëlle - Wednesday, Mar 31, 2004 at 10:37
Wednesday, Mar 31, 2004 at 10:37
Rohan,
Its Bob at the moment
Rohan and Baz - thanks very much for the prompt reply - at least it makes the decision easy !
Bob
FollowupID:
314469
Follow Up By: Member - Rohan K - Wednesday, Mar 31, 2004 at 11:04
Wednesday, Mar 31, 2004 at 11:04
Bob, if you can find a suitable (common/popular) larger size that is still legal, I'd go with it. While the speedo reading will change (by about 3%) most vehicles understate the actual speed by a few % anyway and if uncertain, you just drive at 107 kph intstead of 110.
The little bit of extra lift and the larger footprint you get are worth going up in size if you can.
FollowupID:
314473
Reply By: flappan - Wednesday, Mar 31, 2004 at 12:56
Wednesday, Mar 31, 2004 at 12:56
I would recommend 265/75/R16 regardless.
Coopers or BFG , its a matter of opinion.
I have BFG's on all mine , but admit , I would have like a set of Coopers. I found Coopers to be $50 a tyre dearer , but I couldn't see them being a better tyre as such (not the ST's anyway).
As for the size, slightly larger is always handy , but being only 10mm narrower really means stuff all.
AnswerID:
52646
Follow Up By: Baz (NSW) - Wednesday, Mar 31, 2004 at 13:18
Wednesday, Mar 31, 2004 at 13:18
Bob, go with the same size you have now 275/70/16 in the BFG/ATs then there will be no hassle's old one's off, new one's on, and your off on your trip, easy !!!
Baz.
FollowupID:
314494
Reply By: dogart - Wednesday, Mar 31, 2004 at 19:09
Wednesday, Mar 31, 2004 at 19:09
Bob,
I've just put the new Bridgestone A/T's the 694's (not the 693'S)
on the Jackaroo size 265/70R16.
Fantastic. Did
Kalbarri for 10 days, soft sand, mud and rock, excellent.
Cost $228 each fitted.
look at www.tirerack.com for some good reviews on tyres
my 2c worth anyway!
cheers
wolf
AnswerID:
52695
Reply By: Member - JohnR (Vic) - Wednesday, Mar 31, 2004 at 21:54
Wednesday, Mar 31, 2004 at 21:54
Folks,
Everyone is talking about tyre size limits, sorry I have a number of questions.
Are they limited in each state and what are they in each state where there is a known limit?
Is it an arbitary limit and how long has the limit applied for?
What basis is the limit applied on?
What are the legal and financial penalties applying?
At what stage of wear are the tyres measured to be non compliant?
I would have thought there were other things that would have been more offensive like some lightng possibilities and the lift that some use.
AnswerID:
52731
Follow Up By: Member - StevenL - Thursday, Apr 01, 2004 at 00:42
Thursday, Apr 01, 2004 at 00:42
John,
My research indicates that most states (certainly my state - SA) have referenced their motor vehicle standards Acts to adopt the National Australian Design Rules. These indicate that the outer diameter of any replacement wheel/tyre combo must not exceed the outer diameter of the largest listed wheel/tyre combo on the wheel/tyre placard affixed to the vehicle, by 15mm. I have heard that it used to be 3% but that now it is just a flat 15mm.
The example is my Prado where it is difficult because of the limited availability of 17" tyres for off-road use. The tyre placard says 265/65R17. Mathematically the outer diameter (OD) of this size tyre is ((256mm x 0.65) x2)+(17" x 25.4) = 776.3mm. The recommeded Cooper replacement is A/T's in 265/70R17. Using the maths the OD for these is 802.8mm but Coopers brochure lists them as actually being 31.4" (797.6mm). This is still an increase of 21.3mm which would be technically illegal.
In the face of this I asked my tyre dealer what the story was and he said he would have to check as he was not sure but he had fitted quite a few of these and had no problems. Maybe he actually knew but did not want to lose the potential sale????
My Toyota dealer also showed me another Prado ready to be delivered to a customer where the dealer had done the fitting of the Cooper A/Ts as a pre delivery option. Again I asked "is this legal" and the response was "as far as we know, yes".
Go figure!
As to your last question, tyres are considered to be at the end of their working life at a tread depth of 1.6mm.
Steven
FollowupID:
314565
Follow Up By: Member - JohnR (Vic) - Thursday, Apr 01, 2004 at 05:21
Thursday, Apr 01, 2004 at 05:21
Steven, thanks for your comprehensive reply. The 15mm is often quoted but as to the height or axle height or diameter there is usually a missunderstanding I think.
The tread depth is always of course for water evacuation and in some circumstances like in some muds and clays the Coopers would be too shallow at that tread depth of 1.6mm one would imagine.
FollowupID:
314567
Reply By: Member Colin - NSW Bungendore - Wednesday, Mar 31, 2004 at 22:56
Wednesday, Mar 31, 2004 at 22:56
As far as I am aware, the regulations regarding
tyres sizes,
suspension lifting, lights etc. are, or will be Aust wide. Of course the rego systems vary from state to state - I dont think WA has any checks, NSW is annual.
The other issue is insurance - if you have a prang we know what the Ins Co will do - if the car isn't standard - or the modifications haven't been checked, you will undoubtably 'do your dough'.
So the moral here is - be careful !
AnswerID:
52735