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I'm thinking of putting mag wheels on my car using my present tyres. Is this safe? Will the car then be a modified vehicle and affect my insurance?

Paul.

From the "Ask Jack" archives - 14 December 2009

I advise some caution here. Even if the mag wheel is the same size (including width) you need to make sure the wheel offset is acceptable for your vehicle.

The amount of offset a wheel has determines where the wheel sits in relation to the inner suspension / brake components and the outer body panels.

The last thing you need is the wheel or tyre fouling on objects especially when turning or when the vehicles suspension is working overtime on undulating road surfaces. The amount of offset can also have a bearing on the handling characteristics the car has, and these may change dramatically in some circumstances if a non genuine wheel is fitted.

Go to a tyre shop and ask if they have a calculator that will determine what a suitable alternative mag wheel would be. Or take the wheel you wish to fit to them and ask for the offset to be measured and compared to what you have as standard.

Sounds like a lot of hard work but people don't realise the importance of the right wheel / tyre combination. Provided the vehicle passes a WOF inspection without the need for a low vehicle compliance certification, then I don't believe you have any legal requirement to tell your insurance company however, it wouldn't hurt to play it safe and let them know and avoid any surprises later if a claim was made.

Let me know what you decide.