3.73 and 4.10 engine rpms with automatic at highway speeds..?

ccdguy · 09-29-2008

Hey guys....

I've tried to find a calculator on the web that would help me answer my question, but couldn't find one. Maybe the forum members could help me decide...

I have an 05 pony 4.0 with an automatic transmission. I need help deciding which gear ration would work best for me. I drive 70%Hwy/30%Cty. Can you guys tell me what would be the approximate rpm range when running on the highway say at my usual 80mpg with either the 3.73s or 4.10???????????? How high would the engine be forced to run at at highway speeds? I don't think that it would be wise to run say.... at 80 and be close to or just over 3K,.... At least that's what I think? Any suggestions would be appreciated. Thanks guys !

GoFastOptician · 09-29-2008

That's a tall order.. I did a random search of "3.73 gears vs rpm" on google and you get a TON of answers. I'd suggest doing that and reading what others have talked about.

Bottom line, a gear swap lets you go faster but may limit your top end speed. I think from what I've read and researched, with our type of engine (4.0L) the 3.73 gears would be a better swap. That's just my opinion

Good luck!

Quote:

Originally Posted by ccdguy

Hey guys....

I've tried to find a calculator on the web that would help me answer my question, but couldn't find one. Maybe the forum members could help me decide...

I have an 05 pony 4.0 with an automatic transmission. I need help deciding which gear ration would work best for me. I drive 70%Hwy/30%Cty. Can you guys tell me what would be the approximate rpm range when running on the highway say at my usual 80mpg with either the 3.73s or 4.10???????????? How high would the engine be forced to run at at highway speeds? I don't think that it would be wise to run say.... at 80 and be close to or just over 3K,.... At least that's what I think? Any suggestions would be appreciated. Thanks guys !

Black05Pony · 09-30-2008

Go drive 80 in your car and note your RPM's.

3.73's will be approximately 375 RPM's higher than what your car runs now.

4.10's will be approximately 750 RPM's higher than what you're running now.

After getting 3.73's installed in my 4.0 manual i'm glad I didn't go 4.10's. They would've been too much gear on the freeway especially with my exhaust which drones a bit. My advice is that if you do more than half of your driving on the highway then go no higher than 3.73's.

ARBY · 09-30-2008

Down here in LA (lower Alabama) most everybody
runs 3.73 unless you do a lot of 1/8 or 1/4 mile
racing !!!

dewness · 10-01-2008

check out this program RPM_vs_Speed.xls Let me know if it works out for you.

Salvatorey · 10-01-2008

Quote:

Originally Posted by Black05Pony

Go drive 80 in your car and note your RPM's.

3.73's will be approximately 375 RPM's higher than what your car runs now.

4.10's will be approximately 750 RPM's higher than what you're running now.

After getting 3.73's installed in my 4.0 manual i'm glad I didn't go 4.10's. They would've been too much gear on the freeway especially with my exhaust which drones a bit. My advice is that if you do more than half of your driving on the highway then go no higher than 3.73's.

+1 beat me to it!