My car has 4.10 gears in the rear. However, I need to be able to drive 65-70mph on almost a daily basis and I don't want to keep the engine reved high while cruising.
Now, here is where it gets difficult (for me anyway). The car currently has the original 13" wheels on it, but I am going to put on 16" wheels with 225/50 tires. What gear ratio should I put in so I can cruise at 65-70mph at 3000rpm?
The current tires are 185/70-R13
The side wall height is 5.1 inches (185 x 70%). 13 + 5.1 = 18.1
The tires on on the 16's are 225/50-R16
The side wall height is 4.43 inches (225 x 50%). 16 + 4.43 = 20.43
I am going 2.33 inches over stock diameter, so that needs to be figured in when determining the gear ratio.
I don't know how to calculate the gear ratio and I was hoping someone here would know how.
A gear ratio of 3.27 would be nice right?