Another tyre question - fitting tyres narrower than specification

Kevin.
The 'minimum' tyre size if printed on the vehicle tyre placard usually located in the glove box, door, or door frame. It'll also be printed in the vehicle handbook.
At a guess I'd say the tyre serviceman is correct.
Ozjohn.

Kevin the dealer is wrong, the 245s are only 14mm smaller in diameter than the 255s, take from the tyre size calculator Tyre Size Calaulator
The legal size bigger/smaller is 15mm in diameter, so your safe by ine mil

hi kevin s
the insurance companies will find any excuse to make your claim null and void if you have under size/over size tyres so just be aware of that important fact
if your unlucky and are involved in a bingle
its your call
cheers

The diameter is 14mm less, so still legal. (But I'd never fit an undersized tyre to a 4wd)
The width is OK for a 7" wide rim.

The big issue is the load index. Is the load index of the 245/70 greater or equal to what is stated on your tyre placard.

Maybe the best thing to do is phone the "transport department" in the state where your vehicle is registered...... the would be able to tell you yes or no and you might also be able to get a copy of the document covering this.

Asking legal based questions on a forum is hit and miss.

Hi Kevin

VSB 14 Link here

Is the national standard for modified vehicles and is pretty much accepted everywhere.

it says

4.1 REPLACEMENT TYRES ON STANDARD (OR MANUFACTURER’S OPTIONAL) RIMS
Some tyre sizes have become obsolete and are no longer available. Equivalent replacement tyres with different size designations may be fitted without specific certification under this Section.
Every passenger car manufactured after 1972 (ADR 24) is fitted with a tyre placard that contains information on original and optional tyres and rims for that vehicle model.
A motor vehicle under 4.5 tonnes GVM which is required to comply with ADR 24 may be
equipped with tyres other than those listed on the tyre placard provided that:
? the load rating of the tyres is not less than the lowest load rating listed on the tyre placard of the vehicle or equivalent variant of that model vehicle;

It also says

4.2.4 Overall Nominal Diameter
The overall diameter of any tyre fitted to a passenger car or passenger car derivative must not be more than 15mm larger or 26mm smaller than that of any tyre designated by the vehicle manufacturer for that model.
The overall diameter of any tyre fitted to:
• 4WD passenger vehicles specifically designed for off-road use (typically MC ADR
category). All wheel drive (AWD) vehicles including those AWD vehicles that may be
certified as MC ADR category, (also commonly known as soft roaders) are not
included in this category;
• 4WD goods vehicles and their 2WD equivalents if the chassis and running gear are
essentially the same as the 4WD version (N ADR category); or
• any medium weight goods vehicle (NA2, NB ADR category).
Must not be more than 50mm larger or 26mm smaller than that of any tyre designated by the vehicle manufacturer for that vehicle.

Hope this helps

regards

A

Don't believe the National Code of Practice NCOP has been adopted in Queensland yet.

They've been stuffing around about it here for years.