With the number of gears constantly increasing, do modern auto transmissions still have overdrive?

This is from Wikipedia.

As popular cars became faster relative to legal limits and fuel costs became more important, particularly after the 1973 oil crisis, the use of 5-speed gearboxes became more common in mass-market cars. These had a direct (1:1) fourth gear with an overdrive 5th gear, replacing the need for the separate overdrive gearbox.[1]
With the popularity of front wheel drive cars, the separate gearbox and final drive have merged into a single transaxle. There is no longer a propeller shaft and so one meaning of "overdrive" can no longer be applied. However the fundamental meaning, that of an overall ratio higher than the ratio for maximum speed, still applies.[1] Although the deliberate labelling of an overdrive is now rare, the underlying feature is now found across all cars.

Jim

My assumption say yes, anything with a ratio less than 1.0 is technically overdrive, right?

My 2015 Mercedes C300 has a 7 speed auto.
5th: 1.00:1
6th: 0.82:1
7th: 0.73:1

The overdrive gear in my dad’s 1950 Ford had free-wheeling capability. Going down a hill, the engine just turned at idle speed. I know of no cars that have that capability nowadays.

I'm pretty certain that all manufacturers still need OD to make the federal fuel requirements. Late model Corvette and other GM vehicles with the six, eight and ten speed transmissions have OD.

https://www.corvetteforum.com/...sion-gear-ratios.jpg

quote:

Originally posted by Pipe Smoker:
The overdrive gear in my dad’s 1950 Ford had free-wheeling capability. Going down a hill, the engine just turned at idle speed. I know of no cars that have that capability nowadays.

Some Mercedes cars have a 'glide' feature that does something similar to this.
IIRC, it's the DCT FWD models (CLA/GLA/A)

quote:

Originally posted by maxwayne:
With the number of gears constantly increasing, do modern auto transmissions still have overdrive?

It’s to the point where the question could be, “are there any vehicles sold in US without overdrive (<1:1 gear ratio)?

Not uncommon to have multiple overdrive gears with the multi-speed transmissions these days. I'm guessing there is not an automatic without overdrive these days.

My 66 Mustang has a 1:1 third gear. Makes for about 3000+ rpm at 75. Ever drive at or above 3000 rpm for an extended period of time? Not fun IMO.

quote:

I know of no cars that have that capability nowadays.

My late model SAAB 96 (circa 1976) had the freewheeling feature. Alas, SAAB itself is no longer on the new car market.

An overdrive is simply a gear ratio of less than 1:1. Every manual and non-CVT automatic has had it in at least its top gear for many years. With six- or more speed transmissions, the top two or even three gears may be overdrive.

I was driving my 2018 Accord last night. Keeping up with traffic on a California freeway, in Sport mode my revs were 2300; shifting out of Sport they dropped to 1800. I haven’t looked at the manual, but that’s got to be substantial overdrive.
And there’s no more “shifting out of overdrive” going downhill, just hit the paddle shifters a couple of times if you need to.

quote:

Originally posted by Pipe Smoker:
The overdrive gear in my dad’s 1950 Ford had free-wheeling capability. Going down a hill, the engine just turned at idle speed. I know of no cars that have that capability nowadays.

Not necessarily recommended.

quote:

Originally posted by az4783054:
I'm pretty certain that all manufacturers still need OD to make the federal fuel requirements. Late model Corvette and other GM vehicles with the six, eight and ten speed transmissions have OD.

https://www.corvetteforum.com/...sion-gear-ratios.jpg

My car has PRND and button for Sport mode. No 1,2, or O

My 2018 F-150 has a 10 speed transmission. I have no idea of the ratios of the respective gears.
MPG of over 22 on freeway is like crack to a truck owner...
s

All of them have overdrive, hence the promotion of the overdrive function is no longer useful. Went the same way as fuel injection, electric lights, self starting, or the advertising of unleaded gas.

quote:

Originally posted by sorenson:
My 2018 F-150 has a 10 speed transmission. I have no idea of the ratios of the respective gears.
MPG of over 22 on freeway is like crack to a truck owner...
s

Here you go The secret to the V-8’s improvements is primarily the new 10-speed automatic transmission, which uncorks more of the 5.0-liter’s potential in both highway and stop-and-go conditions. The previous F-150 5.0-liter came with only six gears, which didn’t do the high-revving V-8 any favors; it took too long to get the engine into its power-making range. The 10-speed’s aggressive gearing gives the engine many more options (four, to be exact), and the first six gears are shorter than before: 4.7, 2.99, 2.15, 1.77, 1.52 and 1.28:1 versus the six-speed’s 4.17, 2.34, 1.5, 1.14, 0.86 and 0.69:1 gearing. The 10-speed’s 7th gear is a 1:1 ratio, while 8th, 9th and 10th are overdrive gears.

My '17 Mazda Miata has a 6 speed manual trans, rear wheel drive. There is NO overdrive in the trans. Sixth gear is a 1:1 ratio. Mazda says that eliminates gear friction losses in the trans by sending power straight through, saving fuel. It runs much higher RPMs but gets ~40 MPH.

quote:

Originally posted by sjtill:
I was driving my 2018 Accord last night. Keeping up with traffic on a California freeway, in Sport mode my revs were 2300; shifting out of Sport they dropped to 1800. I haven’t looked at the manual, but that’s got to be substantial overdrive.
And there’s no more “shifting out of overdrive” going downhill, just hit the paddle shifters a couple of times if you need to.

If it's a 1.5l Accord, you have a CVT, so Sport may just hold it to a higher ratio than D.

If the 2.0T Accord, then it's got the 10 speed, and Sport mode may be holding it in a lower gear, then upshifting when moving to D.

I'm with the above comment on the opposite. Is there ANY available automobile transmission today that does not have an overdrive.
I am willing to say no on face value but maybe there is some oddball out there.

quote:

Originally posted by hrcjon:
I'm with the above comment on the opposite. Is there ANY available automobile transmission today that does not have an overdrive.
I am willing to say no on face value but maybe there is some oddball out there.

2 posts above you.
2017 MX5, 1:1 in 6th gear, with the 6MT.