Apologies up front. This has probably been asked many times but hopefully my situation is slightly different:

Firstly, The workshop manual PDF I have says that the stock tyres on a MY97 Impreza Wagon (GF8EK8D) should be 205/55R15 but I have seen conflicting views on that. Could anyone confirm please?

But what I would really like to know is why the speedo reads ~10mph out. The car currently has 195/60R15s on it, which calculators say should only reduce speed by 1.4%. When I am doing 62mph on the speedo, the satnav tells me that I am doing 50mph. So I doubt it is just the tyre size that is causing the speedo difference. Any ideas please?

 

The list I have says the standard tyre is 195-60-15.

Presuming it's a Sport rather than a Turbo etc.

Is it a UK car or an import?

My Turbo is about 5 mph out at 70mph, so speedo says 70, sat nav says 65 ish.

 

Hi Trogg,

Mine's a MY97 Turbo wagon. I did get my tyre info from a torrent downloaded workshop manual so I could have the wrong info.

 

I got my info from here but it doesn't have the tyre size for your model listed.

Hopefully someone else can help.