2013 convertible 3.7 automatic gears
04-20-2019, 04:56 PM
#1
Thread Starter
Join Date: May 2012
Posts: 21
2013 convertible 3.7 automatic gears
Hey guys,
I have a 2013 3.7L v6 automatic Convertible. I have had this car for about 4 years and I have 95k on it now. The car has the stock 2.73 rear gears on it. The car has always been incredibly slow to get up to speed, and when I bought it I didn't understand much. In other words bad acceleration. I have done numerous things to try to correct this over the years...
- I have an aftermarket cold air intake.
- I have a pedal commander to improve the throttle body response
- and I have a Bama tune from American Muscle.
None of these things have really improved the acceleration on this car and after reading, people say that I should swap out my rear end gears.
So I have some questions. I called some places and they recommended that I put in the 3.73gears to make the car more fun without gas mileage taking a big hit.
1) How much will this affect my gas mileage? I'm getting about 20mpg combined driving around Long Island NY with the stock 2.73gears.
2) Will my car get less traction if I do this. As this is my daily driver it still needs to have traction in rain and snow.
3) Will it make the car accelerate smoother then the 2.73 gears or will it be jerky as if there is less throttle delay?
I made an appointment to do the gears on Friday the 26th. I really want to know if I'm doing the right thing before I go through with it. Please give me some feedback on this.
Thanks all! Looking forward to your responses.
I have a 2013 3.7L v6 automatic Convertible. I have had this car for about 4 years and I have 95k on it now. The car has the stock 2.73 rear gears on it. The car has always been incredibly slow to get up to speed, and when I bought it I didn't understand much. In other words bad acceleration. I have done numerous things to try to correct this over the years...
- I have an aftermarket cold air intake.
- I have a pedal commander to improve the throttle body response
- and I have a Bama tune from American Muscle.
None of these things have really improved the acceleration on this car and after reading, people say that I should swap out my rear end gears.
So I have some questions. I called some places and they recommended that I put in the 3.73gears to make the car more fun without gas mileage taking a big hit.
1) How much will this affect my gas mileage? I'm getting about 20mpg combined driving around Long Island NY with the stock 2.73gears.
2) Will my car get less traction if I do this. As this is my daily driver it still needs to have traction in rain and snow.
3) Will it make the car accelerate smoother then the 2.73 gears or will it be jerky as if there is less throttle delay?
I made an appointment to do the gears on Friday the 26th. I really want to know if I'm doing the right thing before I go through with it. Please give me some feedback on this.
Thanks all! Looking forward to your responses.
04-21-2019, 12:55 AM
#2
Banned
Join Date: Jan 2018
Location: Pennsylvania
Posts: 2,327
2.73 to 3.73 is a large jump, and will effect fuel mileage on the highway. For a daily
driver, you never want to go over a 10% increase gearing. Optimally, 2.73 to a 3.0
is what that would mean. 3.55s are available, so that's your best bet for a daily.
That 3.73 will also mean you're on the fuel pedal going down some hills instead
of picking up speed coasting down a hill.
Your car will have the same traction if you have TCS enabled.
driver, you never want to go over a 10% increase gearing. Optimally, 2.73 to a 3.0
is what that would mean. 3.55s are available, so that's your best bet for a daily.
That 3.73 will also mean you're on the fuel pedal going down some hills instead
of picking up speed coasting down a hill.
Your car will have the same traction if you have TCS enabled.
04-21-2019, 05:25 AM
#3
Don't fear the gear. I went from a 2.73 to a 3.73 on my old '95 GT automatic and it was the best mod I ever did on that car.
Ford watered down the 3.7 V6 automatic into a grandma car by giving it a sluggish throttle response, and lumbered it with ridiculously tall 2.73 axle gears so they could brag about it achieving 31mpg on the highway, but that meant the car's top speed was achieved in 4th gear leaving 5th/6th effectively as overdrive gears. It also makes acceleration in each gear feel slow.
The 3.73 gears will transform the your car into the animal it should have been while barely affecting gas mileage. As for the tune, ditch BAMA and go with Brenspeed. Jerky driving has nothing to do with the axle gearing. It's caused by oversensitive throttle tuning and a twitchy right foot.
To make a slight change to 08MustangDude's quote:
"That 3.73 will also mean you're lifting off the accelerator and using engine braking going down steep hills instead
of constantly using the foot brake and cooking the brake pads."
Ford watered down the 3.7 V6 automatic into a grandma car by giving it a sluggish throttle response, and lumbered it with ridiculously tall 2.73 axle gears so they could brag about it achieving 31mpg on the highway, but that meant the car's top speed was achieved in 4th gear leaving 5th/6th effectively as overdrive gears. It also makes acceleration in each gear feel slow.
The 3.73 gears will transform the your car into the animal it should have been while barely affecting gas mileage. As for the tune, ditch BAMA and go with Brenspeed. Jerky driving has nothing to do with the axle gearing. It's caused by oversensitive throttle tuning and a twitchy right foot.
To make a slight change to 08MustangDude's quote:
"That 3.73 will also mean you're lifting off the accelerator and using engine braking going down steep hills instead
of constantly using the foot brake and cooking the brake pads."
Last edited by Dino Dino Bambino; 04-21-2019 at 05:32 AM.
04-21-2019, 10:24 AM
#4
Moderator
Join Date: May 2006
Location: Michigan again!
Posts: 8,579
It's more than just a rear end gear you need to consider; you also have to think about the transmission and how it is set up. On the 2013 automatic a 3.73 is too much. You will short shift from 1st to 2nd because of the transmission.
On the 2013/14 automatic the optimal gear is 3.55. Long enough for the 1-2 shift, quicker acceleration. You don't take a big hit on MPG (the 2.73 is great for MPG, not so great for acceleration). You won't get the jerky feeling that you spoke about with the 3.55 - the 3.73 and 4.10 you will get that feeling because of the 1-2 shift.
On the 2013/14 automatic the optimal gear is 3.55. Long enough for the 1-2 shift, quicker acceleration. You don't take a big hit on MPG (the 2.73 is great for MPG, not so great for acceleration). You won't get the jerky feeling that you spoke about with the 3.55 - the 3.73 and 4.10 you will get that feeling because of the 1-2 shift.
04-21-2019, 10:31 AM
#5
Moderator
Join Date: May 2006
Location: Michigan again!
Posts: 8,579
You really can't compare various years and the rear end gear without considering the changes in the transmission. Comparing the results on a 1995 to a 2013 isn't valid -- every different set ups. Even comparing the 5R55 found in the 2005-10 to the 6R80 transmission isn't a valid comparison because again, very different set up.
04-21-2019, 02:51 PM
#6
Banned
Join Date: Jan 2018
Location: Pennsylvania
Posts: 2,327
I did that once, went from 2.86 to 3.64, and it tore right through 1st gear in "D"... If I
wanted to really run it, I used auto-stick to shift, to eliminate the short-shift. This was on my
prior 5-speed auto '07 Charger, with the NAG1 transmission. I could not find a 3.19 or round
about, so I picked up the 3.64 for $50.00 on eBay, 2-hour swap with IRS... I was getting
upwards of 30+ MPG with a tune and the factory 2.86 gears, from 27 to 28. When I put the
3.64 RII in, it went back down from 30 to 27 -28 highway. I Ran the car to Virginia and back
quite often. Used to run ~2800 RPM in O/D at about 70, that went to ~3100 with the 3.64 RII.
wanted to really run it, I used auto-stick to shift, to eliminate the short-shift. This was on my
prior 5-speed auto '07 Charger, with the NAG1 transmission. I could not find a 3.19 or round
about, so I picked up the 3.64 for $50.00 on eBay, 2-hour swap with IRS... I was getting
upwards of 30+ MPG with a tune and the factory 2.86 gears, from 27 to 28. When I put the
3.64 RII in, it went back down from 30 to 27 -28 highway. I Ran the car to Virginia and back
quite often. Used to run ~2800 RPM in O/D at about 70, that went to ~3100 with the 3.64 RII.
04-21-2019, 10:04 PM
#7
Thread Starter
Join Date: May 2012
Posts: 21
It's more than just a rear end gear you need to consider; you also have to think about the transmission and how it is set up. On the 2013 automatic, a 3.73 is too much. You will short shift from 1st to 2nd because of the transmission.
On the 2013/14 automatic, the optimal gear is 3.55. Long enough for the 1-2 shift, quicker acceleration. You don't take a big hit on MPG (the 2.73 is great for MPG, not so great for acceleration). You won't get the jerky feeling that you spoke about with the 3.55 - the 3.73 and 4.10 you will get that feeling because of the 1-2 shift.
On the 2013/14 automatic, the optimal gear is 3.55. Long enough for the 1-2 shift, quicker acceleration. You don't take a big hit on MPG (the 2.73 is great for MPG, not so great for acceleration). You won't get the jerky feeling that you spoke about with the 3.55 - the 3.73 and 4.10 you will get that feeling because of the 1-2 shift.
04-24-2019, 08:34 PM
#9
Thread Starter
Join Date: May 2012
Posts: 21
It's more than just a rear end gear you need to consider; you also have to think about the transmission and how it is set up. On the 2013 automatic, a 3.73 is too much. You will short shift from 1st to 2nd because of the transmission.
On the 2013/14 automatic, the optimal gear is 3.55. Long enough for the 1-2 shift, quicker acceleration. You don't take a big hit on MPG (the 2.73 is great for MPG, not so great for acceleration). You won't get the jerky feeling that you spoke about with the 3.55 - the 3.73 and 4.10 you will get that feeling because of the 1-2 shift.
On the 2013/14 automatic, the optimal gear is 3.55. Long enough for the 1-2 shift, quicker acceleration. You don't take a big hit on MPG (the 2.73 is great for MPG, not so great for acceleration). You won't get the jerky feeling that you spoke about with the 3.55 - the 3.73 and 4.10 you will get that feeling because of the 1-2 shift.
04-25-2019, 06:27 AM
#10
Moderator
Join Date: May 2006
Location: Michigan again!
Posts: 8,579
My 2013 was a convertible, automatic as well. The 3.55 was the perfect gear in my opinion for overall balance. And I was actually quicker at the drag strip than the guy with the 3.73 and the one with the 4.10 because they could take off fairly quickly but the gearing was wrong for the top end because they got into the 3 and 4 too soon. Part of it is 'bragging rights' like you said, and the calls of "don't fear the gear". But you have to take into account the transmission as well. The 6R80 is very different from the AOD in the older cars or the 5R55 in the 2005-10 cars. Some of the comments that you see are from people who don't have a 2013/14 and don't take into account the difference.