I was recently told that driving my cars (both automatics) at low RPM's will damage the engine over time. Where I live the highways speed limits range from 80kph/ 50mph to 100kph/ 62mph and even if I speed 15 kph above the limit the RPM's never seem to crack 2,000 RPM with either of my cars (unless climbing up a hill). For context my driving habits are normal, following the speed of traffic, I perform regular maintenance and neither car (2012 Mazda 3 and 2023 Mazda CX-9) have given any problems or performance issues.
Would it be beneficial for the cars lifespan to be manually changing the gears every once in a while to get into the high RPM's or putting the CX-9 into sport mode to shift at higher RPM's? Or does this really matter?
@chucktobias appreciate it. Haven’t noticed any lugging
Usually not a problem with automatic transmissions, at least not with modern ones. Some older automatics that are totally hydraulic/mechanical (no electronics) can be reluctant to do part-throttle downshifts due to wear or being out of adjustment.
hat’s what I always thought but appreciate the reassurance.
Unfortunately the old Italian tune up stays around the 2k rpm. If you exceed 30kph above the speed limit your car car get impounded here
That's not what I meant by "drive it like you stole it". Lol. Almost anywhere if you drive 30 km/hr over the limit, your car could be impounded. What I meant basically was if your car has a Sport mode option, delay your upshifts so the RPMs will increase and get the crud out of your engine. Drive aggressively, without pushing the pedal to the metal, up to the speed limit every once in a while. On the highway, I drive in the so-called slow lane but sometimes I will aggressively accelerate up to speed. 3-4k RPMs. Both my truck and Mustang have peak torque at around 4,200 RPMs (the same engine is in both my truck and Mustang). Ever since I figured out how much gas my vehicles consumed when I would go 75 on the Interstate, I backed completely off. It's become almost and art for me with coasting out red lights. The speed limit in my neck of the woods is 65 MPH on the highway. I do 5 under the speed limit in the slow lane, but like I said, occasionally I aggressively accelerate on the on-ramp to the highway.
In an automatic, you really don't need to worry about that. If the load is too great for the gear, an automatic will downshift on its own, at least if it's a pure automatic.
If it's not, (you can perform "manual" shifting with paddle shifters), and you leave it in top gear while substantially increaseing throttle input, that is lugging the engine. Leave it in pure automatic mode, and you won't have the problem.
You might want to drive like you stole it every once in a while to get rid of carbon buildup, aka, the good ol' Italian tune-up.
@justin-shepherd that’s what I always thought but appreciate the reassurance.
Unfortunately the old Italian tune up stays around the 2k rpm. If you exceed 30kph above the speed limit your car car get impounded here
@justin-shepherd you don't need to speed. Just accelerate hard once in a while. (for example overtaking or merging onto highways), and make sure to get the engine good and hot with extended high speed trips every now and again.
By driving it like you stole it, I meant to drive aggressively to the speed limit every once in a while, then back off.
Interestingly I just ran across a description of what lugging can do to an engine in an online article about the 1960s GMC "Toro-Flow" diesel truck engine. From about halfway into the article:
It is easy to see how misapplication of the Toro-Flow in demanding high gross weight trucks led to a rash of often spectacular bottom-end failures. Lugging a TF in a high-GVW truck up a steep grade with the accelerator floored would literally pound the bearings right out of it if it didn’t bust the crankshaft first.
