4:10 ??????? Help ??????

[MrHall1]

Can someone please break down to me what this 4:10 means and does for our MM's. I am not ashamed to say I am lost and have no idea what this is. Thanks in advance

[RF Overlord]

It's actually 4.10:1...it's the ratio between the number of teeth on the ring gear compared to the number on the pinion. It means the driveshaft will turn 4.1 times for every turn of the axles. The higher the number, the greater the torque multiplication, so there's more apparent power, but the lower the car's top speed as the engine reaches it's maximum RPM at a lower road speed.

It also generally means lower fuel economy as the motor turns faster for a given road speed, but there's always a tradeoff anytime you want improved performance. The good news is that the drop in MPG is minimal for the Marauder as the car was designed to have 3.73s or 4.10s from the factory, but it got nixed by the bean counters and 3.55s were installed.

[MrBluGruv]

It also generally means lower fuel economy as the motor turns faster for a given road speed, but there's always a tradeoff anytime you want improved performance.

I've always been curious what the magic number is that doesn't rob fuel economy. While it does turn higher RPM, in theory the engine would have to do less work to maintain the same speed, where does that tradeoff converge?

[ctrlraven]

http://www.autos.com/aftermarket-parts/the-pros-and-cons-of-installing-410-gears



Ford Mustang enthusiasts know that to be a serious threat at the drag track, it is necessary to upgrade your gearing to at least 4.10 gears. Most late model Mustangs and many other sports cars come equipped with standard 3.55 gears in their rear differential, however by adding 4.10 gears they can effectively make their drag times faster and deliver more power to the wheels faster.

What Is All the Fuss over Gear Ratio?

Gear ratio has a great deal to do with how your car performs and handles under load. The gear ratio is the ratio of how many times your engine has to turn the crankshaft to turn the rear wheels one rotation. Therefore, the higher the ratio (4.10 gears compared to 3.55 gears) the higher the gearing and the greater number of rotations before the rear wheels turn. This equates to a greater amount of power transferred to the wheels. Late model Mustangs and sports cars tend to have a lower gearing to accommodate more highway driving, however this can cause them to feel sluggish or slow on the track. In many instances, a simple fix is to install 4.10 gears with the stock motor of the Mustang which should "wake up" the feel of the Mustang on the track, but still provide highway drivability.

The Pros to 4.10 Gears

The obvious pros of installing 4.10 gears is that the car's performance will improve on the track, but with negligible effects to the highway driving. If your car is equipped with an overdrive, you may not even notice a difference in gas mileage with the new higher gearing. Depending on the transmission that you have installed, you might even be able to adjust the overall gearing so that the final drive of your car is nearly the same while in overdrive, but allows you to take advantage of the new gearing in the lower transmission gears.

The Cons

The main negative aspects of installing 4.10 gears lie in performing transmission modifications in general. If the gearing in your differential is changed in a significant way, then the speedometer calibration is likely to be affected which will make your speedometer inaccurate. The new gearing can affect transmission shift points as well (on automatic transmissions, but this is a non-issue for manual transmissions). Custom tuning by a qualified speed shop is normally a good fix for both of these issues.

The final con associated with 4.10 gears is obviously a drop in fuel economy. Switching from a gear set of 3.55 or 3.73 to 4.10 gears will affect your gas mileage slightly as your engine will be turning more times to rotate the rear wheels once. In most cases you can expect to see a drop of 1 to 2 miles per gallon, but in many cases fuel economy was never a concern for performance enthusiasts anyway.

Installing 4.10 gears is an effective way to wake up a stock sports car and making it a real contender on the drag track on the weekends, but still able to be used as a daily driver too.

[MrHall1]

Guys thank you so much!!! I know have a understanding of what's going on.

[Blackened300a]

Sparta performance, a vendor of this site has a great deal on 4.10 ring and pinion with a install kit. You'll just have to find a shop near you to install.

[slickster]

How much will it cut et's

[03sport007]

I drive the same way to work everyday. 5 miles at 35 to 45 mph and 2 miles at 65 mph. I actually get better gas millage now with 4.10's.


Bone stock with a heavy foot 18MPG.
Driving with a very light foot the best I got was 21mpg.
After my tune and a even heavier foot I would get 15mpg.
After installing the 4.10's the gas millage went back to 18mpg.

[ctrlraven]

How much will it cut et's
That depends on numerous factors like what other mods you have.

With a tune and 4.10 gears most members have been in the mid-low 14 sec range. Add intake and torque converter with a good launch - high 13's.

[JoeBoomz]

I drive the same way to work everyday. 5 miles at 35 to 45 mph and 2 miles at 65 mph. I actually get better gas millage now with 4.10's.

This is possible, as with the 4:10's the engine has to work LESS to get you up to speed than with the 3:55's. However crusing at 60+ MPH you'll be running a few hundred RPM higher (and using more gas), so the savings are minimal.

[SC Cheesehead]

This is possible, as with the 4:10's the engine has to work LESS to get you up to speed than with the 3:55's. However crusing at 60+ MPH you'll be running a few hundred RPM higher (and using more gas), so the savings are minimal.

I tracked mileage before and after installing my 4.10's, and in the long run, saw virtually no change in mpg (on the highway), but a substantial improvement in performance.

In town mileage dropped, but I attribute the majority of that to my driving style.

[Mr. Man]

I tracked mileage before and after installing my 4.10's, and in the long run, saw virtually no change in mpg (on the highway), but a substantial improvement in performance.

In town mileage dropped, but I attribute the majority of that to my driving style.
Yeah but your a geezer. See what happens when you get your car up to 65 mph:D