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3.73 or 4.10s

13K views 45 replies 27 participants last post by  GrnBullittgirl 
#1 ·
I'm considering gears in my 01 bullitt and i've read a lot. What should I get 3.73s or 4.10s?
 
#2 ·
use the SEARCH button. There is tons of info on this forum about this topic.

(but to summarize, get 3.73 if you do alot of highway driving, or have a supercharger, or care about optimum gas mileage.
Get 4.10 for better performance, and you'll lose a few mpg.
(I have 4.10's and would never go back.)
 
#5 ·
I have 373's. I heard the 410s would make 1st gear useless, but I think if you drive it right, its fine. I wish I would have done the 410's.
 
#6 ·
Like what was mentioned, this topic has been discussed to death in the past decade, so a search will pull up tons of info/opinions.

Me? I went to 3.73's in 3230's early life....as what has been said, they were a good compromise...but for me...just not quite enough. Lived with them for a good 50k.
Then went to 4.10's, and LOVE them. As stated above, you're in and out of 1st in a flash, and mpg goes down a bit....but...for me and my cammed engine I need the higher RPM's to get into the cam curve on the hiway.

For all the stated differences, many have chosen another compromise and gone the 3.9 route. It really does boil down to what kind of driving you do the most, what kind of performance/feeling you are after, as well as what type of power plant you are or intend to run...
 
#7 ·
+1 on Kurt's reply.

It all depends upon what you want to use your car for and what supporting mods you have. I have had 3.27, 3.73, 3.90, and 4.10 in my Bullitt. I really like my 3,90 and a great compromise between the 3.73 and 4.10. There is a BIG difference between 3.73 and 4.10. Unless you plan to go FI in the future, I would go with either 3.90 or 4.10.

You will really like the gears no matter which ratio you chose. Even the 3.73 is a very noticeable improvement over the stock 3.27. Gears are THE best bang for the buck mod.
 
#8 ·
Hello Robert, as stated above this has to be one the most discussed topic on this (and most performance) site.

One interesting thing that can happen with 4:10, is that some people saw improved gas milage with 4:10s. It all depend upon how you normally drive. If you do a lot of stop and go, when you pull aways you do not have to use as much "gas pedal". You can pull off much easier using less gas. If you drive in a hilly area, then you do not have to use as much gas to climb the hills. Let the gears work for you so less working of the gas pedal. These combinations will work to improve you milage.

On the other side of the coin, if you do a lot of high speed driving (75+) your engine will be turning more RPM and you will see reduced milage. The biggest killer of gas milage with the gears, is the fun. The car will be so much more responsive, you cannot ignore the urge to just play with it. This will greatly hurt you gas and TIRE mileage.

There really is no right or wrong answer. Any of them will put a grin on your face.
 
#9 ·
I ordered 4.10's, and received 3.73's ... The car was already at the Install shop, so the 3.73's went in...

The first thing I noticed was the much shorter time I spend in 1st, 2nd and yes, even 3rd...
The second thing I noticed was I was getting better gas mileage.

Besides the gears and the new exhaust, my car is completely stock... I spend more time on the freeway, I believe, but a decent amount of time driving city streets. This is my daily driver, so I will live with the 3.73's, even though I was disappointed not getting the 4.10's.

Just thought I would chime in with my recent experience...the gears and exhaust are 6 months old.

Oh, my son drove the car the other day (he's only driven it a couple of times in the past) and he had forgotten about the new gears...when he got back, he was grinning from ear to ear!!! He LOVED the new response time!
 
#10 ·
So, Treva. This begs the question. What were you getting for gas mileage, and what do you get now? What grade/octane of gas are you using?

Just as a for instance, my factory stock Bullitt routinely gets between 25/28, city/highway driving, on unleaded regular.
 
#11 ·
DavidMidgley said:
So, Treva. This begs the question. What were you getting for gas mileage, and what do you get now? What grade/octane of gas are you using?

Just as a for instance, my factory stock Bullitt routinely gets between 25/28, city/highway driving, on unleaded regular.

I use unleaded regular also.
I was getting about 240-245 per tank and now I get about 260-270.
 
#15 ·
Could the "improved Gas Mileage" be due to not changing the computer to read the shorter gears? Speedo will read as if the car still has 3.27's but driving with 3.73's...

You know what I mean?

I had 3.73's in #5055 and did not change the speedo. My car did "appear" to get better mileage.

Anyone what to chime in on this?
 
#16 ·
^^^ no...when 3230 had the 3.73's (and re-programmed into the chip), I saw a jump in MPG, especially on extended hwy cruises. It was not uncommon for me to get 26-28 with a fully loaded Bullitt with the 3.73's, as compared to 24-26 with the stock gears. I figured it had more to do with the engine running at peak torque curve at hwy speeds with the 3.73's...but regardless...it got measurably better than stock.

You can generally expect the mileage to drop compared to stock with 4.10's.
But not that it is an issue for me anymore with the stageIII 302....best I can get keeping an egg between my foot and throttle is 18-19. It's just all fun and grins now!
 
#21 ·
Seriously???
Many of us use our cars for DD, but still want to improve performance. How happy would you be if your Bullitt got 5mpg after making a mod? That is clearly exaggerated, but to say that fuel mileage makes no difference if you are seeking performance is ridiculous.
 
#23 ·
the timeless, ageless, no definitive answer to the question above almost all...except maybe exhaust. as I have indicated prior....I have had both in the same car. without a doubt, I was happier with the 3.73's than the 4.10's for my style of driving, which is: DD and periodic long trips. gas mileage definitely went down with the 4.10's on trips. and I love performance, but I also care about the gas mileage. I am not made of money and my money tree in the back yard is now completely barren thanx to my kids thinking they can go back there anytime and pluck some..

Ford decided that the best compromise between performance and economy was the 3.73's by virtue of what their performance package offers for the new Stangs. if it is good enough for them.....good enough for me.

if anyone, at least to me, asks the question about gas mileage vs performance...if you have a Mustang, you already want some performance. with that, if you have a Stang, you will probably mod it. nowadays, if you aren't concerned at all about the gas mileage..........you must be rich or you only drive your car on the weekends if it doesn't rain.. or it's a race car.
 
#26 ·
if anyone, at least to me, asks the question about gas mileage vs performance...if you have a Mustang, you already want some performance. with that, if you have a Stang, you will probably mod it. nowadays, if you aren't concerned at all about the gas mileage..........you must be rich or you only drive your car on the weekends if it doesn't rain.. or it's a race car.
Well, I ain't rich, I race it and it a DD.

So where do I fall in your catergories?
 
#25 ·
I've had Bullitts with 3.73 and 4.10 now.

For me it boils down to this;

If the car has boost, 3.73 are great. If it doesn't then the 4.10 are my preference.

I've got the 4.10 gears now but when I do the Kenne Bell it will probably end up going back to 3.73 gears.

JR
 
#28 ·
I just pulling your chain Snake!

My whole point is, if you are buying a V-8 anything car, gas milage should have been the last check mark on the list of "Must Haves"
 
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