Traction control

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Fri 13 Sep 2002 06:09
Traction control - L'escargot
When I fit the space-saver spare on my Focus, it causes the traction control to be intermittently activated. Presumably, because the spare is a slightly smaller diameter and therefore rotates quicker, the traction control system thinks that that wheel is losing traction. I know that I can switch off the traction control, but I wish that the handbook had warned me. The first time I used the spare, it took me ages to realise what the solution was.
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Fri 13 Sep 2002 09:51
Traction control - Dynamic Dave
I was always led to believe you fitted the space saver wheel to the non driving axle. ie, front wheel drive, if you get a puncture in the front tyre, you fit the space saver to a rear wheel and in turn fit the rear wheel to the front. Obviously vice versa for rear wheel drive.
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Fri 13 Sep 2002 17:24
Traction control - Cyd
You will find that although the space saver is narrower than the std tyres, its rolling diameter will be the same. Therefore the spare will rotate at the same speed as the other wheels.

Space saver tyres, being narrower, will not have as much grip as the std article - it could therefore be that it was actually losing traction. When using a space saver you should limit your speed (max 50mph) and generally drive more gently than usual.
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Sat 14 Sep 2002 10:03
Traction control - L'escargot
You will find that although the space saver is narrower than
the std tyres, its rolling diameter will be the same.


Not on my car.

I proved this by trying to fit a standard wheel/tyre into the spare wheel well ~ it just would not go in. The problem was not the width, but the diameter. I had hoped that I could buy another standard wheel/tyre to avoid the aggro associated with using the spare i.e. having to change the wheel twice each time, and having to drive at a restricted speed (manufacturers' recommendation) while the spare was in use. I have checked the handbook, and the spare and the standard wheels are of all the correct size and type. There is no mention of only fitting the space-saver in a particular location.
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Sat 14 Sep 2002 10:25
Traction control - Cyd
How much was the difference? If it's considerable I'd be concerned about straining the diff (up to 1/2 inch would be OK but an inch or more would be bad I'd say).
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Sat 14 Sep 2002 11:17
Traction control - L'escargot
How much was the difference? If it's considerable I'd be concerned
about straining the diff (up to 1/2 inch would be OK
but an inch or more would be bad I'd say).


Didn't measure it. All I know is that the standard wheel/tyre won't go in the spare wheel well. I'm sure Ford know what they are doing when they specify the space-saver spare wheel, but I'm just a bit surprised that they don't warn about unwarranted activation of the traction control system. At the time that it occurred, I only had to drive in a 30 mph area to the tyre dealer and as soon as I found that the traction was playing up I kept both my speed and my acceleration to a minimum. Other than that (and a few other minor irritations) I am very pleased with my Focus. After 60K miles from new, I can happily report that it is the most reliable car I have ever owned. My most unreliable car was a 1967 Hillman Imp. Starting to ramble on now, as well as showing my age !!
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