Changing to a lower profile tyre?

[icemancupra]

Been offered some toyo PROXES T1-R, for cheap. However they are 205/40/17, currently mine are pirelli pzero's 205/45/17.

I'v been on the calculator on the web, i know my speedo will read about 4mph out at 70, is this the only problem?

thanx guys n gals

 

[keithr]

Well ive got 205/40/17 as standard on my cupra (pirelli' pzero's) so cant see how you'd have any problems.

 

[icemancupra]

funny that mines the same lol. I need to start looking before I ask

mines a cupra

 

[Yella Beeza]

Been offered some toyo PROXES T1-R, for cheap. However they are 205/40/17, currently mine are pirelli pzero's 205/45/17.

I'v been on the calculator on the web, i know my speedo will read about 4mph out at 70, is this the only problem?

thanx guys n gals

In answer to your question (though it's hypothetical now), if you had the 45 profile tyres and changed them to 40's - expect the speedo to read higher figures than the true reading (ie 4mph at 70mph), give slightly better acceleration, and a lower true top speed (though this wouldn't be indicated by the speedo).