Mummichog

Car Gear Ratios?

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So, I've been reading a lot about Mustangs and the motorheads love to talk about gear ratios.  Everyone has their opinion on what is best.  Best for drag times, best for gas mileage, best for drivability........   My car has a 3.73 rear.  I'm still trying to figure out if that's good or bad.

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The lower the gears, the worse the gas mileage. Better low end power. At least thats how it works with 4x4 rigs. My jeep has 3.73 gears with the tow group. Rubicons have 4.10. Those offroad guys get into the 5's.

 

 

A quick read seems to indicate not to eff with your gears

 

 

Edited by MitchellNJ

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3.73 is a good all around rear. There are better for track performance and there is better for highway driving. 3.73 is right about where you want to be if it's your daily driver that you like showing off it's get up and go. 

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Most engines generate max hp at around 5000-5500 rpm. Your new mustang generates 430 hp at those rpms. At idle it might be less than 100 hp. If you wanted a drag car, you'd want a small gear ratio so that you keep the rpms up and stay in that power area, so larger wheels with more grip can get down the track faster. Downside is the gas mileage is horrible. If your offroading you'd want a big gear ratio so you don't spin the tires very easily and dig into the ground. Downside is on street driving your pickup speed would be horrible due to taking forever for the engine to get into the power band.

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Sounds reasonable.  A lot of these guys on the Mustang forums are always trying to get faster 0-60 and 1/4 times.  I'm happy that my car puts me back in the seat when I hit the gas and it has a nice growl.  Of course, fast drag times are good for bragging rights.  And I will tell people whatever the guy from Motortrend or Car and Driver did when he test drove the car.  I'll just have to figure out what gears the test car had.  :D

 

One day I'll take it to a track and see what I can do myself.

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Got my answer:  

 

Equipped with the available 3.73 rear axle ($395), our 5.0 needed just 4.3 seconds to hit 60 and only 12.8 at 110.8 mph to knockout the quarter mile. To answer the million-dollar question: Yes, it's quicker than both the 426-horsepower Chevy Camaro SS (4.5, 12.9 at 110.7) and the 425-horse Dodge Challenger SRT-8 (4.6, 13.1 at 108.4). It's also not that far behind the 540-horse supercharged 2010 Shelby GT500, which requires 4.1 and 12.4 at 116.0. In the league of naturally aspirated muscle cars, the new Mustang GT is in a league of its own.

 

Source:  MotorTrend.  

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Its part of your transmission.

 

Another way to look at it is the smaller the tire the taller the gear.   Vica versa.  IE my jeep feels about the same when it had 3.73s on 30s as it does with 4.10 on 33s

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2 hours ago, Mummichog said:

So, I've been reading a lot about Mustangs and the motorheads love to talk about gear ratios.  Everyone has their opinion on what is best.  Best for drag times, best for gas mileage, best for drivability........   My car has a 3.73 rear.  I'm still trying to figure out if that's good or bad.

automatic? street wise 3:73 or 3:55, I had 4:10 on my Chevelle fun on the street but terrible for highway 4K at 60mph

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57 mins ago, Sandflee said:

automatic? street wise 3:73 or 3:55, I had 4:10 on my Chevelle fun on the street but terrible for highway 4K at 60mph

Must have been awesome milage, like a prius?

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