Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: bob.dent on 22 September 2011, 13:13:28

Title: diff ratio's
Post by: bob.dent on 22 September 2011, 13:13:28: I know this has probably been asked before but will a diff from a 2.6 auto estate be compatible with a 3.2 auto estate? Not sure if the ratio's are the same. :-/
Title: Re: diff ratio's
Post by: cem_devecioglu on 22 September 2011, 13:20:13: http://www.omegaowners.com/forum/YaBB.pl?num=1312469626

http://www.omegaowners.com/forum/YaBB.pl?num=1163895469

hope this helps
Title: Re: diff ratio's
Post by: cem_devecioglu on 22 September 2011, 13:24:04: 4.22 instead of 3.90 your car will be faster but will consume slightly more
Title: Re: diff ratio's
Post by: Osprey on 22 September 2011, 13:28:42: ... and run higher revs at cruising speed.
Title: Re: diff ratio's
Post by: bob.dent on 22 September 2011, 14:28:06: Thanks guys, so not the way to go for better fuel economy! ::)
Title: Re: diff ratio's
Post by: tigers_gonads on 22 September 2011, 15:10:10: Mines a 2.5 manual gearbox / dif on a pre facelift with a 3 ltr engine

Anybody know which gear ratio's / diff I have ?
Title: Re: diff ratio's
Post by: cem_devecioglu on 22 September 2011, 15:12:40: Quote
Mines a 2.5 manual gearbox / dif on a pre facelift with a 3 ltr engine

Anybody know which gear ratio's / diff I have ?

depending on the model year you can check from my second link :y
Title: Re: diff ratio's
Post by: tigers_gonads on 22 September 2011, 15:14:02: Quote
Quote
Mines a 2.5 manual gearbox / dif on a pre facelift with a 3 ltr engine

Anybody know which gear ratio's / diff I have ?

depending on the model year you can check from my second link :y

97 (pre facelift)

facelift engines only on that chart ;)
Title: Re: diff ratio's
Post by: cem_devecioglu on 22 September 2011, 15:15:04: Quote
Quote
Quote
Mines a 2.5 manual gearbox / dif on a pre facelift with a 3 ltr engine

Anybody know which gear ratio's / diff I have ?

depending on the model year you can check from my second link :y

97 (pre facelift)

facelift engines only on that chart ;)

97 original manuals 2.5 have 3.70 as far as I know :y

not sure for 3.0 :-/
Title: Re: diff ratio's
Post by: cem_devecioglu on 22 September 2011, 15:18:10: Quote
Thanks guys, so not the way to go for better fuel economy! ::)

if you quickly shift up, fuel consumption wont change much imo..
Title: Re: diff ratio's
Post by: Jimbob on 22 September 2011, 15:56:52: if you send me reg's ill happily check what they left the factory with.
Title: Re: diff ratio's
Post by: feeutfo on 22 September 2011, 15:58:52: Got 4.2 in mine. Slightly quicker, but some of that is negated by the slightly over size tyre/wheel combo. And the weight of the lpg tank etc. It's a couple of hundred rpm higher at, say, 80.
Not massive.

May as well get the right one Bob, if your not after any performance increases. There must be plenty about if not plod or LSD spec.
Title: Re: diff ratio's
Post by: Jimbob on 22 September 2011, 16:03:48: Bob, yours is 3.90:1 ratio :y
Title: Re: diff ratio's
Post by: tigers_gonads on 22 September 2011, 16:57:04: 3.7 Diff in mine ( cheers jimbob )

Always thought my car should be a little quicker of the line :-/

Do all the diffs have the same torque rateing ?
Title: Re: diff ratio's
Post by: Kevin Wood on 22 September 2011, 17:19:19: 3.90 in an auto and 3.70 in a manual is the usual spec.

The difference in diff ratio between auto and manual is due tot he automatic gearbox having a taller ratio in top gear so I think the two come out pretty much even when it comes down to it.

In fact, 2woody did some nice plots to show exactly that:

http://www.omegaowners.com/forum/YaBB.pl?num=1312469626

:y
Title: Re: diff ratio's
Post by: Kevin Wood on 22 September 2011, 17:22:25: The auto is actually taller geared than the manual with a 3.9 diff. :o
Title: Re: diff ratio's
Post by: 2woody on 23 September 2011, 18:33:24: Quote from: tigers_gonads on 22 September 2011, 15:10:10
Mines a 2.5 manual gearbox / dif on a pre facelift with a 3 ltr engine

Anybody know which gear ratio's / diff I have ?

you can measure it if you have a sat-nav or GPS device.
Title: Re: diff ratio's
Post by: sjc on 23 September 2011, 22:20:43: Quote from: cem on 22 September 2011, 13:20:13
http://www.omegaowners.com/forum/YaBB.pl?num=1312469626

http://www.omegaowners.com/forum/YaBB.pl?num=1163895469

hope this helps

In the first link (with the top speeds in each gear), the manual 3.90 graph for 3rd gear has a higher top speed than the 3.70???
Title: Re: diff ratio's
Post by: cem_devecioglu on 23 September 2011, 22:48:03: Quote from: sjc on 23 September 2011, 22:20:43
Quote from: cem on 22 September 2011, 13:20:13
http://www.omegaowners.com/forum/YaBB.pl?num=1312469626

http://www.omegaowners.com/forum/YaBB.pl?num=1163895469

hope this helps

In the first link (with the top speeds in each gear), the manual 3.90 graph for 3rd gear has a higher top speed than the 3.70???
yep.. I also see..
Title: Re: diff ratio's
Post by: Kevin Wood on 24 September 2011, 01:18:29: Quote from: cem on 23 September 2011, 22:48:03
Quote from: sjc on 23 September 2011, 22:20:43
Quote from: cem on 22 September 2011, 13:20:13
http://www.omegaowners.com/forum/YaBB.pl?num=1312469626

http://www.omegaowners.com/forum/YaBB.pl?num=1163895469

hope this helps

In the first link (with the top speeds in each gear), the manual 3.90 graph for 3rd gear has a higher top speed than the 3.70???
yep.. I also see..

Hmm. That can't be right. :-\
Title: Re: diff ratio's
Post by: albitz on 24 September 2011, 05:05:17: Quote from: Kevin Wood on 22 September 2011, 17:22:25
The auto is actually taller geared than the manual with a 3.9 diff. :o

Post 98 auto 4.22.1
Title: Re: diff ratio's
Post by: 2woody on 24 September 2011, 09:02:06: maybe I've dropped a clanger - i'll look into it :-[