Gear ratios are an important part of the drivetrain, and they affect how your vehicle performs. There are two gear ratios: first-gear and overdrive/low-gear ratios. The first-gear ratio refers to the number of teeth on a pinion gear with respect to its ring gear (i.e., 3.73:1 or 4:1).
Overdrive/low-gear ratios refer to the number of teeth on a pinion and ring gears combined (i.e., 3.55:1 or 2.73:1). These numbers can be used interchangeably; however, it is important to know what each one means before making an informed decision about which ratio is right for you.
What is a Gear Ratio?
A gear ratio is the ratio of the number of teeth on the driving gear (the smaller gear) to the number of teeth on the driven gear (the larger gear). The number of revolutions of the driving gear that are required to make one revolution of the driven gear. The lower and more precise this number is, the higher quality of your transmission will be.
3.73 Gear Ratio Explained
The 3.73 gear ratio is the most common gear ratio in trucks and SUVs, and it’s also a good choice when hauling or towing heavy loads. The higher the number of teeth on your ring gear to pinion gear face, the lower your overdrive ratio will be.
For example, if you have a 4L80E transmission with an AAM axle assembly, this means that your off-road gearing would be 2.64:1 (43/13) while highway gearing would be 3.73:1 (23/13). If you’re using your truck as a daily driver or hauling on long trips at highway speeds frequently, then you might want to consider getting something other than 2WD with low gears such as 4×4.
3.55 Gear Ratio Explained
If you’re looking for the best gear ratio for your truck, 3.55 will give you good performance on the highway and will perform well in light towing tasks.
In addition, if you’re interested in racing or need something heavy-duty enough to tow a trailer behind it, this might be a good option for you as well. The reason why this gear ratio has such a large range of uses is due to how it works with engine RPMs and vehicle speed.
When driving at lower speeds (such as on the highway), there are fewer revolutions per minute in comparison with when driving faster speeds (like city driving).
This means that more torque can be applied using 3.55 gears because there is less resistance from spinning too fast which causes slippage between the tires and their contact point with the road surface during acceleration periods—you may have heard this term before wheel spin!
Pros of 3.73 Gear Ratio
The biggest benefit of the 3.73 gear ratio is its ability to handle heavy loads and high speeds. If you want to tow a heavy load, such as an RV or trailer, or if you want to drive at high speeds on the highway or off-road course, then this gear ratio would be most beneficial for your vehicle.
The 3.73 gear ratio is also beneficial for off-road driving because it provides the highest torque with less engine RPMs. This allows drivers to gain more traction than they could with other gearsets.
Cons of 3.73 Gear Ratio
The disadvantages of 3.73 gear ratio are:
- Increased fuel consumption – You will use more fuel to go faster.
- Higher wear and tear on the engine – Your engine will be pushed harder, which means it will wear out faster.
- Decreased acceleration – Acceleration is slower because you have less torque and power at low RPMs.
- Increased noise – The higher RPMs cause more vibration, noise, and heat in your car’s engine compartment; all of which reduce reliability over time.
Pros of 3.55 Gear Ratio
The 3.55 gear ratio is best for highway driving. When you’re going long distances at high speeds, you don’t have to make as many gear changes because the ratio is lower and more efficient.
If you’re hauling around a trailer or some other heavy load that requires extra power, then the 3.55 gear ratio will also come in handy as it’s better suited for towing.
This may not be an issue if you just want your car’s drivetrain to last longer (which it will), but if saving money on fuel is top priority than this could be an important consideration as well.
Cons of 3.55 Gear Ratio
The most obvious disadvantage of a 3.55 gear ratio is that it will make your acceleration slower, and your top speed lower.
The engine needs to do less work at the same speeds as in a higher gear, so you’ll never be able to get up to highway speeds quite as quickly.
This means that it takes longer for you to get where you’re going—whether it’s across town or across the country. And even when you’re driving in third gear, which keeps your engine running at its peak power output, you’re still not going to be able to go any faster than about 70 mph (112 km/h)
. Another disadvantage is that fuel consumption can be worse with a 3.55 gear ratio versus other common options like the 4.10 or 4.30 gears commonly found on sportier trucks like Jeeps and Mustangs.
This is because these vehicles have engines designed for speed rather than efficiency, they’ll use more fuel when they’re driving at higher rates of acceleration due to using smaller gearsets. This happens in order to maintain their speeds while climbing hills or accelerating quickly out of corners on curvy roads.
Both Gear Ratios are Efficient But Depend On Your Driving Style
If you drive on the highway and don’t need to take off quickly from a stoplight, the 3.73 gear ratio is better for you. If you drive on city roads and often have to accelerate from a dead stop, the 3.55 gear ratio is better for you. Both gear ratios are efficient but depend on your driving style.
You should now be able to make an informed decision on whether or not you want a 3.55 or 3.73 gear ratio for your car. I hope this post has helped you learn about the pros and cons of each gear ratio so that you can choose which one works best for your needs.
Robert Anderson is a world class motorhead who rebuilt his first carb at age 10, his first engine at age 15, and completed his first full hotrod build when he was just 18! Previously, he has ran a part warehouse, delivered pizzas, and managed the service department for a $20 million/year revenue dealership. Robert knows cars like few others and he is passionate about sharing his knowledge.