Overdrive transmission what is

This is the reason why having more gears equals a better fuel economy. The higher the number of gears in the transmission, the lower the gear ratio will be.

That is why trucks have nine, ten, and even fourteen gears. They can easily conserve fuel as they travel long distances in very high gears. Almost all car models have some kind of overdrive gear, and it applies to both manual and automatic transmissions.

However, if you are talking about the classic overdrive gear with a button on manual transmissions, it is an old feature that applied to some older car models. Older automatic transmissions had the same type of overdrive gear that is engaged automatically instead of using a button to engage it.

Yes, the overdrive function reduces the RPMs of the engine at a higher speed and therefore saves a lot of gas for you. If you are driving at too low RPMs, it can increase fuel consumption instead, though. It is never a good idea to tow a car in overdrive gear. When you are towing a car — you would prefer to have as much torque as possible. The overdrive gear is giving exactly the opposite, lower torque.

Using it at lower gears and speed will cause more stress on the engine, especially when you need more torque. It is better to just use it at a higher speed, like highway cruising, for example.

In most car models, the overdrive gear is way over the capacity of the maximum speed of your car. Theoretically, it makes your car go faster though if you have enough power for it! Ask any car question in our new community!

Magnus is the owner and main author of MechanicBase. He has been working as a mechanic for over 10 years, and the majority of them specialized in advanced diagnostics and troubleshooting. Certified Automotive Diagnostic Technician. The last two times on checking the transmission oil level it has been higher than usual. It was always on the hot mark until now. Could this be due to the ambient air temperature being high? All other engine levels are normal.

Contents show. What is overdrive? It will also make your engine more fuel efficient , meaning that it will make the most out of the power it generates. As a result, the output speed of the engine will be faster than its input speed. Anyone who loves high-speed cruise control and good fuel economy will benefit from the overdrive gear.

If your automatic transmission vehicle has a manually selectable overdrive gear, you will often need to push a button to activate. Once that button is pressed, the transmission upshifts to the highest gear possible. Basically, the overdrive allows the engine power to go right to the transmission while locking the torque converter.

This will improve the performance of the vehicle and save you money on fuel at the same time. Higher speeds usually put more strain on your engine. This is then further enhanced by the latest crop of transmissions that feature 10 or 11 forward gears, all of which can combine to produce fairly nifty fuel consumption figures.

You may not have to look too far back for automatic cars featuring overdrive, but the technology has been out of date for quite some time in manual transmissions.

Saying that, an overdrive unit certainly had its place back in the day and showed one of the first ventures towards creating reasonable fuel economy on a long cruise. Please confirm you agree to the use of tracking cookies as outlined in the Cookies Policy. Sign in or register. Michael Fernie 5 years ago. Remind me later. Share Tweet Email Whatsapp. The overdrive unit can be seen bolted to the rear right of this Triumph TR3's transmission. Let Engineering Explained take you through the ins and outs of gear ratios.