How's first gear? I am doing a set of 18" wheels. (from stock 16"s) will the 18's kind of negate the gear upgrade w/ 3.73's? I don't feel like turning 3grand going down the HW.

I still have to contact the manufacturer to see if they have 3.83's or 3.90somethings.

 

Not sure what you mean with the switch to 18's.... if you correctly match the stock tire diameter with the tires you put on the 18's, there will be no affect on RPM or torque multiplication. There may be some minor power loss due to inertia effects of the larger diameter wheels, but that's going to happen no matter what gears you are running.

With stock tire diameter, and 3.42 gears, you should be seeing about 1,800rpm at 80mph. With the 3.73's and keeping the tire diameter the same, you would see 1,960rpm. For the 4.10's at 80mph you would be turning 2,160rpm at 80mph.

 

I have 16's stock right now. If I upgrade to the 18's and leave the gears, the vehicle speed will increase slightly due to the change in larger diameter.... right?

So If I install gears that would turn 'slower' (3.73's) w/ the 16's.......THEN throw on the 18's, would that negate the gear change?? ...I think that's the best way I can explain it. Am I making too much out of this?? I think I'm confusing myself the more I think of it...


OK, a car w/ 4.10's would accelerate faster but loose top speed w/ 16" wheels. The same car w/ the same gears switches to 18" tires, wouldn't accelerate as fast but would slightly gain top speed..


Aren't 4.10's noisier than the smaller gears?

 

No, you match the new tire diameter to match the stock diameter with your new combo.

In other words, you run a smaller tire height than stock when you run 18" wheels.

For example, a stock 16x8 wheel runs a 245/50/16 tire, and an SS or WS.6 17x9 wheel runs a 275/40/17. Same diameter at the end of the day.

 

Your tire diameter is the wheel diameter plus the side wall X 2 (top and bottom). So as stated in the above posts, even through you're increasing your wheel diameter from 16" to 18", your tires will have a reduced side wall height to properly fit, therefore you're overall diameter will remain at approximately 26". Go to tiretrack.com and look at their +1 and +2 sizing info.