GrdLockV6

So I went from the 3.23's to some 3.42's in my new rear-end. I'm not gonna bother getting it reprogrammed until I get around to buying a Predator.

So when my speedo says I'm goin 60, am I really going faster or slower? And how much faster/slower? I just wanna make sure I'm not cruisin along thinkin I'm doin 60 and I'm really doin like 70, or cruisin at 60 and really only doin 50 and wondering why I'm being passed like crazy

I wouldn't think it'd make more then a 2-3mph difference though but I'd just like to know.

Mikael

You're going slower than you think. I'll let someone else do the math.

1fastWS6

3.23 to 3.42 = ~6% change in driveline speed, all else being equal.

This means you're going 6% slower than your speedo reads (and racking up miles 6% faster too. At 60 mph, you're only going about 57mph.

BTW, why would you get a 12 bolt and only put 3.42's in it??? That seems kinda silly to me.

6speedZ28

You got a 12 bolt and only went with 3.42's? I would have said hello 3.73's if you had an auto and hello 4.10's if you had a M6. (sorry I didn't look to see which one you had )

Z-Attitude

Enter your info here
http://www.f-body.org/gears/

KamaroL98

I went from 2.73s to 3.42s and it made a pretty big difference. Like if i was going around 65 it said 90mph..... Also remember, your odometer is recording more mileage then your actually traveling until you get that little problem fixed.

GrdLockV6

I do lots of freeway driving... my gas mileage is already bad, will be even worse once I get my TC put on, and even worse when I get my cam. The 3.42/3.73's won't make that much diff on the strip, so I went w/ 3.42's.

stik6shift00

cant you auto tap it and then fix the needles?? cause i have 3.73's and i think it says how fast im going...but maybe not?