17’s - they slow you down much

[jimbo1]

ok, earlier this week i fitted some 17inch chrome alloys to my valver. compared to my standard 15inch alloys, the weight difference wasnt that great. driving around town roads upto 50mph, there is no difference in perfromance, other than amazing cornering ability due to the increased offset- et 40 i think.

however, once over 50-60 and cruising on the motorway in 5th at 70-80mph the car accel;erates alot slower. b4 with the 15s the car wud take off wen the throttle was mashed, now it hardly accelerates. a gear change to fourth is the only way to make decent progress.

has any1 else experienced this when fitting 17 inch alloys to the car, i take the reason for this is the increased rolling radius and circumference weighthas an increased effect on speed changes when in a high gear?

jimbo

 

[viceroy]

Okay, basically youll accelerate slower by the percentage difference in diameter percentage difference between the original wheels and the new ones, so lets say you used to get from 0-62 in 7.0 seconds and your wheels are 3 percent bigger then youll now get to 62 in 7.12 seconds

Youll notice it much more at speed since your engine has so much less power in reserve

 

[BenR]

The weight might not of increased but youve moved the moment of the majority of teh weight furthr from the spinnig axis....or the spindle. Thus its got greater inertial forces.

The increased offset will REDUCE track and your grip is comming from a wider tyre and larger contact patch.

 

[Adams_16v]

the 17s on my car slow it down a lot. When i changed back to them i was quite pi55ed off. but id just bough 4 new tyres so they were staying for a bit lol. Cant wait to get some 15s back on for drivability......but the 17s look the nads. grrr

 

[Ben H]

Ive had some refurbd Phase2s on for about six months now and the car handles a lot better. I havent noticed a massive speed difference, apart from it being much more reluctanant to as right at the top end (not an issue unless you travel at 3am in the morning on non-camerad motorways).