Anyone else notice the RWD auto G gear ratios don't match the factory specs?
Registered User
Joined: May 2005
Posts: 498
Likes: 0
From: MN, western subs
Speedo calibrations are always off. They never seem to be right. Set your cruise at exactly 60mph, watch the mile markers and have a stop watch. When I'm going 60 it takes my stock-tired 6MT coupe just under 58 seconds to do a mile. Which calculates to my actual speed is 62.5mph (great for speeding, I'm going faster than I think I am). I've tried this on many highways and have acheived the same results. My wifes 3.5SE is the quite opposite, her car at 60mph takes over 62 seconds to complete a mile. Her car even has that digital readout in the trip display which reads the car going 57, while at the same time the needle says 60, so go figure. Nothing is perfect.
Originally Posted by DaveB
But the G35 doesn't use the old school wire driven speedometer cables that are wildly off above 110mph. The G35 uses speed sensors that read data off the rotation of the wheel. This has to be very accurate because the stability and traction control programs rely on this data. I have a hard time believing there is 8mph speedometer error in this system at the top of 4th. That's pretty bad.
Registered User
Joined: Dec 2003
Posts: 2,514
Likes: 5
From: Marietta, Georgia
Have you measured and corrected for the tires loaded radius?
A tire rolling underweight [800 pounds on each rear] will be ~~1" shorter in the loaded radius........each brand size will vary with its particular side wall stiffness and inflation pressure and temperature. Measure center of wheel to ground 12" not 13".
TC slip function of efficiency vs rpm vs temperature.
A tire rolling underweight [800 pounds on each rear] will be ~~1" shorter in the loaded radius........each brand size will vary with its particular side wall stiffness and inflation pressure and temperature. Measure center of wheel to ground 12" not 13".
TC slip function of efficiency vs rpm vs temperature.
Thread
Thread Starter
Forum
Replies
Last Post
