Poor handling with low-profile tyres on 520d

HELPDESK:Answering all your motoring queries

From L OBeirne: I purchased a BMW 520d SE automatic last September. While on holiday in France, the steering had no feel whatsoever on the motorways, as if you were on rails: when a correction was made the car oversteered and needed a counter correction.

I informed the dealership of the problem and they took the car in to check the geometry setup. All seemed okay to them.

I then drove the car again on the Naas carriageway – nothing had changed. It was taken back again and I was told a complete test had taken place. BMW Ireland sent out a technician who said there was no issue.

After getting quite annoyed with the salesman, he rang me back with an offer to supply a set of the original size wheels and to offer my wheels at the trade counter for sale.

I have not taken up this offer yet, as I bought the car for its nice look and, as one would presume, better handling from the low-profile tyres.

According to BMW Ireland’s director of sales and marketing, Michael Nugent, the firm’s national technical manager drove the car with you and couldn’t replicate the problem. “The test drive included driving at up to 120km/h on a motorway.”

Nugent says: “We should bear in mind that 20-inch wheels with wide, low-profile tyres give very different and more direct feedback from the steering due to the much wider contact area and the lower profile.

“The response to a change in direction is noticeably quicker and the tyres will tend to follow the camber of the road. This is a characteristic of all wheels of this type, which is one of the reasons customers choose to purchase them. Unfortunately this owner is not happy with this, which is a shame given that they were on the car when he purchased it and I understand he took the opportunity to test drive it before purchase.”

The dealer who sold the car has offered to replace the 20-inch wheels with the 18-inch M Sport wheels. They also offered to make a contribution to the additional cost of the 20-inch wheels.

I would suggest that you take up the offer. It will not have such a detrimental affect on the car’s image and it’s likely to make the car’s handling more amenable to your driving style.

Greater tyre tread contact with the road can lead to a different steering feel that owners might not be expecting. If there’s a lesson, it’s to be sure you pay attention to the handling traits during a test drive and not just the practicalities.

Send your queries to Motors Helpdesk, The Irish Times, Tara St, Dublin 2 or motorshelp@irishtimes.com