I am trying to deside between 3.73's and 4.10's.. I used this website to figure out my RPM's @ 70 mph.. Am I figuring this correctly, I'm no math wizard but I think I have it right..

First off since I am trying to figure it out in 6th gear 3.42's would be 21.82mph/500rpm not the 1000 because the gear ratio is .5:1 in sixth, correct? With stock tires (25.5" height) obviously. That means w/...

3.42's (stock) at 70mph im turning 1604 rpms... seems about right
3.73's at 70 mph would be 1750 rpm
4.10's at 70 mph would be 1923 rpm

That doesn't seem bad at all really for 4.10's.. What do you guys think? I do want to be able to drive it on the highway with out stopping at every gas station.. Its not a daily driver anymore so highway travel wouldn't be that often. Opinions?

Thanks for your input,
Craig

 

4.10's

 

Before you decide on gears decide whether this is a boulevard car (fast from stop light to stop light) or a highway car (primarily used for cruising on the highways or expressways or whatever you guys call them in the East). If it's a boulevard car - use 4:10s as you are only at high RPMs for short periods of time. If it's a highway car - how fast do you normally cruise?? Do you cruise at 75mph or more for long periods - like on tours? If so then go with lower gears than 4:10s.

Age has a lot to do with gearing. The younger you are the higher numbers of gears, because of the "need for speed". The older you get the lower the gear numbers because you look for cruisability and QUIET. Higher gear numbers make everything louder.

 

I like my 4.10s. Im still under 2k rpms at 75 with them, and I think that is pretty good... you dont have to downshift to speed up, and I get good mileage too. (but I have nothing to compare them to)

 

Well I'm not really a "street racer" I like my car too much to loose my license (though i dont shy away from the occational pesky rice rocket or cocky GT). I do like to take it to and from work (about 6 miles) every now and then and to see family which would require highway travel though not more then 2 hours. Basically is a weekend, sunny day driver that I like taking to a show or the track or just the grocery store. Put it this way.. I have put 1500 miles on it since Oct. and that includes a extreamly rare 1000 round trip to Richmond VA. Oh the highway I cruze at about 70, if traffic is moving I'll kick it up to 75 but thats rare.

 

Dude, you said it was a weekend warior, who cares about mileage. Get the 4.10's

 

Just go with 4.10's, you'll never regret it for a second.

 

Only complaint I haver heard from m6 guys with 4.10's is, first gear goes bye real fast. But that sounds like fun to me

 

I am getting 3.73's but mine is a daily driver. With an M6 I would still get 3.73's because with 4.10's you will need to run some sticky tires and watch that 10 bolt more. But if you just want to use it as your mess around or track car I would go with 4.10's. Good Luck.

 

Exactly. I had 4:10's when I still drove it during the week a lot and they aren't that bad, it's pretty much just a weekend warrior now though. It's almost no different cruising on the hwy with 4:10's compared to the 3:42's, it actually made 6th gear more usefull to me and it only changes the rpms by like 200 in 6th. If I was ever able to keep my foot out of it I bet it would actually get pretty good mileage, probably very close to the 3:42's. And 1st gear does go by very fast now.....get the 4:10's