www.jec.org.uk

Hi. Changed rear tyres on my 55 X-Type Monday. Didn't have 225/45/17 at the tyre place so put on 225/55/17. Ever since then,whilst accelerating,orange rectangular warning light flashes on the speedometer dial and car will not speed up,seems to be in limp mode. Could the bigger tyres on the rear be the reason? Perfectly fine before this. Had MOT today and asked them to check,nothing on diagnostic machine came up!! Any answers please??

Indeed that could well happen. I`ve seen this before on an S-type that had been fitted with a mix of inappropriate tyre sizes.

I assume you have the new tyres across one axle, ie across the car?

The difference in profile between the 45 and 55 tyres is probably enough to tell the traction module that, for instance, one set of wheels is going faster than the other. You really do need to have the same sizes all round as printed in your owners handbook. ie identical rolling length/circumference on all four wheels. The change from 45% to 55% will be quite significant.

i would advise going back to the tyre guys and get them to fit the correct tyre size.

Mike K