Interesting question on the legality of the tyre size increase.
In QLD an MC rated 4wd can have up to 50mm larger diameter tyres whereas a passenger vehicle or Soft Roader can have only 15mm larger.
So is the Trailhawk classified as a 4wd or a Softroader?
Did some digging and came up with this:
Quote:
Originally Posted by QLD Regs
For a passenger car, passenger car derivative or ‘soft roader’ (an all wheel
drive vehicle that may be certified as MC ADR category), the overall
diameter of any tyre fitted 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:
• a 4WD passenger vehicle specifically designed for off-road use (MC ADR category other than a ‘soft roader’);
• a 4WD goods vehicle and its 2WD equivalent if the chassis and running gear are essentially the same as the 4WD
version (N ADR category); or
• 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.
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Then I looked at the relevant ADR's:
Quote:
Originally Posted by ADR's - Vehicle Definitions
4.3.3. OFF-ROAD PASSENGER VEHICLE (MC)
A passenger vehicle having up to 9 seating positions, including that of the driver and being designed with special features for off-road operation. A vehicle with special features for off-road operation is a vehicle that:
(a) Unless otherwise ‘Approved‘ has 4 wheel drive; and
(b) has at least 4 of the following 5 characteristics calculated when the vehicle is at its ‘Unladen Mass‘ on a level surface, with the front wheels parallel to the vehicle’s longitudinal centreline, and the tyres inflated to the ‘Manufacturer‘s’ recommended pressure:
(i) ‘Approach Angle‘ of not less than 28 degrees;
(ii) ‘Breakover Angle‘ of not less than 14 degrees;
(iii) ‘Departure Angle‘ of not less than 20 degrees;
(iv) ‘Running Clearance‘ of not less than 200 mm;
(v) ‘Front Axle Clearance‘, ‘Rear Axle Clearance‘ or ‘Suspension Clearance‘ of not less than 175 mm each.
Alternatively, a vehicle that meets the definition of CATEGORY G - OFF-ROAD VEHICLES under Consolidated Resolution on the Construction of Vehicles (R.E.3) of the United Nations Economic Commission for Europe and is in category M1.
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So it has to meet 4 of the 5:
Quote:
Originally Posted by TrailHawk stats
The Cherokee Trailhawk is suspended by MacPherson struts with aluminium lower control arms at the front and an aluminium four-link trailing arm set-up at the rear and rides 25mm higher than the regular Cherokees, giving 221mm of ground clearance and 508mm fording depth.
The Trailhawk also boasts a wider track front and rear (+33mm and +41mm) for improved off-road stability and remoulded bumpers front and rear improve the geometry and taking the approach angle to 29.9 degrees, the break-over angle to 22.9 degrees and the departure angle to 32.2 degrees.
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So to me that means the Trailhawk should be classified as a MC Offroad vehicle? Almost like specifically designed to meet those requirements?
So bottomline putting the 25mm larger tyres (going from 245/65/17 to 245/70/17) is not an issue for the boys in blue or the insurance company?