09-03-2009, 07:29 AM
I am looking to buy a Focus 2006 55 Reg Titanium Model which has 16” 5 spoke alloy wheels. I would like to upgrade these to the 18” wheels currently supplied on the New 2008 Focus Titanium and think these are also on the ST model. I think this will be possible, the only question I have is would the speedometer need adjusting for fitting larger wheels to the car? If so how do I go about doing this, would a independent garage be able to do this or would this have to go to Ford dealer?
Any help advice much appreciated
09-03-2009, 07:39 AM
Going from a 17" wheel to an 18" will offset your speedometer, but the tires you put on will determine the final difference. For example, if you go from 215/45/17 to 215/40/18 sized tires, the difference will be about 0.615% too slow so when the speedo says your going 60mph, your actualy going around 59.6 mph. Going from a 16" tire in a 215/50/16 to an 18" will compound this slightly, making it approx 1.262% too slow. Tires widths, brand, and (occasionally) offset can all affect the final number. A couple of good sites to calculate this:
Yes. An independent garage might be able to adjust this, although several companies and garages specialize in speedometer adjustment. Check your yellow pages. Then again, the difference is slight, and unless you normally push the envelope on the speed limit, I wouldn't worry about it too much.