Dear Car Talk:
When buying my first car (a 1997 Geo Metro), the salesman gave the usual spiel about how great the car was and then added, “Because this is a stick shift, you will also get great gas mileage.” I was sold.
That was 27 years ago. My most recent purchase (2019 Honda Civic Si) was very similar in that the salesman talked about all the great features found in the car, but finished with, “The only downside is that with a stick shift, you will lose a little bit when it comes to fuel economy.”
I have been wondering about this for years now. Can you clear up who is right? Thanks, and love your column!
— Brent
They were both right, Brent.
Over the last 30 years, and particularly over the last 10 years, automatic transmissions have changed — for the better. And they’ve surpassed manual transmissions in fuel economy.
When you bought your 1997 Geo Metro — and an Academy Award goes to the salesman who told you what a great car it was with a straight face — you had two transmission choices. You could get the five-speed stick shift, or you could get the three-speed automatic. The more gears a transmission has, the better it’s able to optimize the gear for the driving conditions, which leads to better fuel economy.
And importantly, on the highway, the more gears you have, the slower the engine can turn in its highest gear at highway speed, which makes a huge difference in mileage. So, in 1997, the stick shift — with two extra gears — was the more efficient option.
Fast (or not so fast, in a Geo Metro) forward to 2019. Your transmission choices for the Honda Civic were a six-speed stick shift or a continuously variable automatic transmission (CVT). A CVT has an infinite number of gear ratios, so it’s always in the right gear. That’s why the same Civic with the CVT gets 3 miles more per gallon.
This is true across the board now. We see a lot of CVTs, and even fixed ratio automatic transmissions that have eight, nine, and 10 speeds. So, at highway speed, a stick shift in fifth or sixth gear has the engine turning at 2,500 or 3,000 rpm at 70 mph, whereas the engine paired to an automatic is turning at 1,500 or 1,700 rpm.
Plus, automatic transmission fuel economy used to suffer due to slippage, which is inevitable when you’re transferring power through fluid. But automatics now have lock-up torque converters that “lock” the transmission into gear at higher speeds. They essentially operate like manual transmissions, without any slippage, when cruising.
There are still reasons people prefer stick shifts. Some like the control, some just find it fun, and some like the challenge of balancing their coffee on their knee while steering and shifting gears. So, if you’re one of those guys, Brent, enjoy. If you’re only interested in fuel economy, though, go automatic next time, if not electric.
