?

anybody know if you can fit bigger or smaller tyres on a pug 405 the
size on at mo is 175x70x14inch,and the tyres on there are budget tyres.

 

I think mine had 185/65/14 on.

 

Presumably the tyre 175 bit is controlled by the rim size and the 14 by the
rim diameter so that would only leave the 70 to play with. Just a
thought, if you reduced the 70 to a lower profile, w2hich would reduce the
circumference of the tyre, would that not have knock on effects on final
drive gear ratios and the accuracy of the speedometer and mileometer? I
seem to remember in the early 60's when "town and country" tyres became
popular there were reports that cars travelled a bit faster than the speedo
reported.

 

If you lower the profile, you can (should!) take wider tyres to get the same
diameter.
But you better ask a tyre specialist about the exact sizes you have to take.
Also the wheelhousing must allow for wider tyres.

maybe this link can help you to get an idea
although it is made for jeeps, I suppose it will also do the job for
"regular" tyres.

http://ptheune.net/~pir/photos/Jeeps/Tires/tire_calculator.php

Grtz,
Eric B.