3.55 to 4.10

[tallpaul]

Could any one tell me how much the gas mileage went down when going from 3.55's to 4.10's? Normal city and highway driving. Was there alot of gear whine?

[bawazir]

one mpg

[SC Cheesehead]

Could any one tell me how much the gas mileage went down when going from 3.55's to 4.10's? Normal city and highway driving. Was there alot of gear whine?

City driving, gotta admit my mileage has taken a hit, but IMO it's due to my driving style much more so than the gear swap. :burn:
On the highway, at 70 mph, you're going to be running about 2,300 rpm with 4:10's, about 200 rpm higher than the 3:55's, which gets the engine running a bit higher up in the power band, so the engine's actually running better. I've compared my "before and after" ave. mpg and there's about a mile per gallon difference.

If you get the gears installed by a knowledgeable shop, I doubt you'll notice any whine.

4:10's and a tune are the two best mods you can make from bone stock.

[-Matt-]

....over 9000

[fastblackmerc]

City driving, gotta admit my mileage has taken a hit, but IMO it's due to my driving style much more so than the gear swap. :burn:
On the highway, at 70 mph, you're going to be running about 2,300 rpm with 4:10's, about 200 rpm higher than the 3:55's, which gets the engine running a bit higher up in the power band, so the engine's actually running better. I've compared my "before and after" ave. mpg and there's about a mile per gallon difference.

If you get the gears installed by a knowledgeable shop, I doubt you'll notice any whine.

4:10's and a tune are the two best mods you can make from bone stock.
+1

You'll lose about 1MPG.

But alot more fun to drive!

Didn't we just go thru this a while ago?

[tallpaul]

Thanks for the info. Maybe I will do the swap. Do you know anything about the MMX driveshafts people recommend? Where do I get one? What is special about them?

[ntd]

+1

You'll lose about 1MPG.

But alot more fun to drive!

Didn't we just go thru this a while ago?

+2 4.10's make these cars come alive

[SC Cheesehead]

Thanks for the info. Maybe I will do the swap. Do you know anything about the MMX driveshafts people recommend? Where do I get one? What is special about them?

Less distortion at speed, reduces the tendency for tailshaft breakage. New, they're about $600, or if you scout around salvage yards you may come across one from a CVPI.

Unless you're going to run consitently over 100 mph, the stock driveshaft should be okay.

[CanadaMarauder]

I didn't notice any MPG drop. Whine means the install is not good and you may have bought the wrong car if your worried about MPG :)

[SpartaPerformance]

4.10 is well worth the 1 mog for the acceleration increase.

[Ktorres1]

Sc cheesehead so you mean to tell me my stock dive shaft is not up to par for strong highway driving? I love top end that being so it's kept me on the wall about 4.10's! Even though I dnt have my tune yet I always ram it well over a 100mph I'd say at least 10x a week, also I have felt some vibration at those speeds and I thought maybe it's just the wind? Also how much faster would be my 0-60 time with the new gears?

[SC Cheesehead]

Sc cheesehead so you mean to tell me my stock dive shaft is not up to par for strong highway driving? I love top end that being so it's kept me on the wall about 4.10's! Even though I dnt have my tune yet I always ram it well over a 100mph I'd say at least 10x a week, also I have felt some vibration at those speeds and I thought maybe it's just the wind? Also how much faster would be my 0-60 time with the new gears?

It's not that it's not "up to par," it's just that the stock aluminum DS will distort at high speed (100 mph+), causing a resonant vibration that can end up in parts failure. The MMX or carbon fiber driveshafts don't have this distortion (at least at speeds a Marauder can reach).

If you want to go with a MMX driveshaft replacement you've got two options: Used or new.

You can search auto salvage yards for the correct CVPI and pick up one of those. Details on what you'll want to look for are here:

http://www.mercurymarauder.net/forum...=matrix&page=3 (http://www.mercurymarauder.net/forum...=matrix&page=3)

Reinhart sells them, will set you back around $600
http://reinhartautomotive.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=12345&Category_Code=9

There are prolly other sources as well, but that's your ballpark price.

As for improvements at the dragstrip, I don't have my timeslips handy, but IIRC, gears and a tune dropped my ET by around a second.

[fastblackmerc]

Sc cheesehead so you mean to tell me my stock dive shaft is not up to par for strong highway driving? I love top end that being so it's kept me on the wall about 4.10's! Even though I dnt have my tune yet I always ram it well over a 100mph I'd say at least 10x a week, also I have felt some vibration at those speeds and I thought maybe it's just the wind? Also how much faster would be my 0-60 time with the new gears?

Since your a regular visitor to ""well over 100MPH" "10x a week", does your MM show any signs of driveshaft vibrate now?

If not, you'll probably not see any with the change to 4.10's.

[Ktorres1]

Well i can't tell if it's been the heavy winds or if it's the drveshaft but I've tooken it many times to the gov limiter of around 120mph. I just wanna be safe at those speeds!

[Ktorres1]

Also what's the highest topend speed the stock 4 speed tranny can hold?

[RF Overlord]

Ktorres, the transmission doesn't care what the top speed of the car is.

For anyone questioning whether the MMC driveshaft is worth is, read this (http://www.tccoa.com/articles/tranny/transmission/page17.shtml) article, written by Jerry Wroblewski. You don't have to have any noticeable vibration for the tailshaft bushing to be ruined, until it's too late.