Tyre Eng Certificates

who did you use for yours?

Ian Prain in Pakenham

Vicroads accredited which is 95% of the 'battle'

contact info?

depends if they go on measured size (some 285's are bigger than others), or marked size of 285.
but yes you do need a cert.

Brian

facts are

1/ 285's are more than 15mm taller than the most common standard GU(275/70/16), and taller again than 265/70/16 which is often on 3lt.

2/ The alternnate placard is for 265/75/16 which is about 5mm taller than standard. (275/70/16)

3/Nissan does not use 285 on other model patrols

4/ As per Truckster - their is up to 10mm difference in 285 tyre diameter and also wheel rim spec - e.g. X Terrains require only 7in rims and everyone else uses 8in

4/ Depending on model - check your handbook - in back of my handbook it refers to an overseas model using 245/85/16 which is a much larger tyye.
I rely on this clause and victorian guidelines which allow 15mm bigger than biggest used on other models , and hence get away with use of even larger diameter tyres than 285 (255/85/16) without a certificate.

Can't comment on other states guidlines

Robin Miller

Robin thanky for setting me straight you are right i was wrong goodyears 285 are 840mm and 265 are 810mm when new ie 30 mm difference.

Still wonder if this difference further affects low speed gearing noticeably,mine is too high geared in my view,but i am told the 4.2 is even higher geared in first gear than the 3litre is that true do you know??

Hi Brian

Yes the 4.2 has same 4.26 1st gear ratio as 3lt (models around 2002) but has a final drive of 3.9 compared to the 3lt & 4800's 4.375, so it has less
rev's.

Going up in tyre size clearly makes it harder to get off the line
but many seem to cope with this change ok.

See how you go taking off in second gear - its not as bad as that but
this gives some idea.

A good dynotune can negate the effect of larger tyres.

Robin Miller

$279 Trade?
Makes my $265 walk in off the street price on Friday outstanding!

Would you like to buy a bridge in Sydney?

If I get a safety certificate with the car it means it's roadworthy and legal

You have never heard of dodgey roadys?

Just cause thats how they sold it to you doesnt make it legal or roadworthy. They can say that you changed the tires, and your gone. your word against theirs..

Whats the oldest rule? Ignorance of the law is no excuse?