not sure how much that will effect the speedo.... basic rule of thumb will be...
15's get 50 series tires...
16's get 45 series tires...
17's get 40 series and so on and so forth...
i would try to find some 45s just to be safe.... i have read that those gatso's are bastards!
My local dealer doesn't do Toyo's at 45mm profile, this is all I can get:
Kumho 712 205/45 R17 Z £81.85
Falken ZE512 205/45 R17 W £84.74
Bridgestone RE040 205/45 R17 W £119.43
Pirelli PO ASSIMETRIC REINFORCED 205/45 R17 W £127.86
Yokohama A539 205/45 R17 Z £130.73
Dunlop SP9000 205/45 R17 Z £136.46
Michelin PILOT SPORT 205/45 R17 W £151.80
Think I'm going for Dunlop SP9000's.
Shout now if any of the others look especially good!
How difficult would it be to get the speedo re-calibrated?
how much should it under read the speed??
40 profile = 884 revs per mile
45 profile = 855 revs per mile (approx)
50 profile = 826 revs per mile
If my can was doing 100mph on 40's, the same speed on the tacho would be actually be:
100 x 884/855 = 103.4mph
I'm pretty good with on-the-fly mental arithmatic, so should be okay... don;t speed by more than 5% and I should be okay
To be fair I'm pretty good with my "10+2"* maths for UK roads already, not that I usually push my luck even that much - just useful when there's somebody being and idiot and tailgating you when they can't overtake.
* "10+2" is the police guide for speed trapping in the UK: 10% of stated speed limit + 2mph.
Hence why everybody "mysteriously" cruises at just under 80mph on the motorways... perfectly safe speed for a modern car on good roads, provided you have a safe stopping distance.... only prob is there's always the fruit-cake who likes to tailgate at that speed too.... "only a fool breaks the two second rule" and all that....
the ride height difference between 40s and 45s is so small you wont really notice...you already knew it would mess with your speedo reading.... the only real difference will be the gap from body to edge of tires. you will have slightly less of a gap due to the thicker wall on the tires.
but it will be all good when you drop the dub!
only prob is that 205/45/17's aren't that common.... I'm going for 40's for my new Toyo Proxes... getting Koni/Eibach shox and springs, plus Eibach sway bars... with that I'll be able to lower the suspension a bit if needed and 205/45/17's won't be as much of a headache... just hte availability of them.
Was gonan go for the Dunlop SP9000's, but they're run-flat, so a harder ride anyway.....