Mustang Evolution Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
27 Posts
Discussion Starter · #1 ·
I have a 99 GT auto, I am considering changing my gearing. Now the big question is 3.90 or 4.10. I do a lot of highway driving.

I talk to an old car guy and he said he had 4.10 in one of his cars back in the day and couldn't go more than 70mph. But off the line it went.
 

·
Registered
Joined
·
3,903 Posts
That's just an old car. 3.90 to 4.10 you won't see any difference in mpg just got with 4.10

---------- Post added at 07:32 AM ---------- Previous post was at 07:32 AM ----------

Especially since you're auto
 

·
Premium Member
Joined
·
6,004 Posts
Read the gears thread in the stickies section of this forum, it's a good read on 4.10s and has a video showing what highway driving is like with 4.10s and a manual.
 

·
Registered
Joined
·
79 Posts
Read the gears thread in the stickies section of this forum, it's a good read on 4.10s and has a video showing what highway driving is like with 4.10s and a manual.
Where's the stickies section how do I get they're .. Ty in advance... Stool learning this site

---------- Post added at 04:15 PM ---------- Previous post was at 04:13 PM ----------

Where's the stickies section how do I get they're .. Ty in advance... Stool learning this site
Stool learning hahaha spellcheck ... Smh. I meant learning ...

---------- Post added at 04:15 PM ---------- Previous post was at 04:15 PM ----------

Where's the stickies section how do I get they're .. Ty in advance... Stool learning this site

---------- Post added at 04:15 PM ---------- Previous post was at 04:13 PM ----------



Stool learning hahaha spellcheck ... Smh. I meant learning ...
Still ... Uhhhhhgggg
 

·
Premium Member
Joined
·
6,004 Posts
Where's the stickies section how do I get they're .. Ty in advance... Stool learning this site

---------- Post added at 04:15 PM ---------- Previous post was at 04:13 PM ----------



Stool learning hahaha spellcheck ... Smh. I meant learning ...

---------- Post added at 04:15 PM ---------- Previous post was at 04:15 PM ----------



Still ... Uhhhhhgggg
On the mobile app it's at the top, right next to where it says Threads.
 

Attachments

·
Registered
Joined
·
1,001 Posts
Here is my "How Fast Can I Go In Each Gear?" calculator, that may help you sort out where you want to go.

Pay no attention to "old car guy"--I am one (68 in April)--they never made a Mustang on which the top speed would be limited to 70 mph with 4.10 gears...
 

·
Registered
Joined
·
1,001 Posts
When changing the gearing is there any recommendation of other parts to change.
It depends on how many miles on the rear-end--more than 80 to 100k (arguably less) I would rebuild the LSD clutch packs, replace all seals (pinion gear and axles), and seriously inspect/question all bearings...
 
1 - 9 of 9 Posts
Top