Holden Commodore: Diff ratios

Question

Holden Commodore: Diff ratios

Holden Holden Advice Holden Commodore Holden Commodore Advice Holden Commodore 2003

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IN ORDER to make my 2003 VYII Holden One Tonner V8 more driveable and to reduce fuel consumption (22 litres/100 km), about a year ago I changed the diff ratio to 3.73:1 (a Holden ratio). Since then it has had front sway bar linkages/bushes replaced under warranty. Now that the front radius rod mounts need replacing (under warranty), Holden has put a ``full warranty restriction'' on the car, citing a ``non-standard diff fitted to vehicle''. Why, when only a minor change has been done at the rear end (using Holden parts), has the vehicle had a restriction put on it?

Answered by CarsGuide

4 May 2006

Carsguide.com.au

MY INFORMATION is that this ute has a 3.46 diff ratio with the manual gearbox and a 3.08 with the auto. Going to a 3.73 would have made fuel consumption worse. I'm surprised you changed to this ratio. In any case, before you changed the ratio you should have had the car checked to determine why its fuel consumption was so poor. There is something wrong with it given the air-fuel ratio is so rich. By changing the ratio you have modified the vehicle, which I'm guessing is why Holden is refusing to cover it under warranty. Continue to talk to Holden to find a solution that is going to satisfy you. If you can't,, then think about resorting to legal action. But before you try the latter, have your car checked by an expert such as Mark Trounsen of Dynomotive to make sure it is as it should be.

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Holden Commodore: Diff ratios

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