Tell your husband to get a clue. Merging onto a highway at that speed is outright dangerous. Putting others at risk to save a tablespoon of gas is completely wrong.
As long as the car isn’t knocking …then it’s probably OK to be in 3rd at 20mph…
Shifting with Tach - The only people who really need to shift with a tach are race-car drivers…In my 40+ years of driving I’ve NEVER used a tach to shift. I think you’ll make a better driver if you don’t look at the tach…but try to shift by feel/hearing.
But if an engine has a horsepower peak of 200 HP at 5000 RPM. Then wouldn’t simply be producing 200 HP at 5000 RPM even if all it took was 1/2 throttle to achieve 5000 RPM. The throttle controls the amount of fuel and air being introduced into the engine, it doesn’t have any bearing in and of itself as to how much power the engine is producing. Like you said when you’re lugging the engine you can floor the throttle and not much will happen. In that case the engine is producing the same amount of power (roughly) as it does at idle despite the throttle being fully open.
"The only people who really need to shift with a tach are race-car drivers…In my 40+ years of driving I’ve NEVER used a tach to shift. "
I agree… Experienced manual shifters can “feel” the motor labor from your seat in rwd cars to the steering wheel and pedals in fwd cars. You’re right, tachs should not be that necessary for driving, but good overall to measure engine performance. I’ve driven and ridden in a Aveo. Even if you shift it correctly, it’s a poor performer. Maybe OP’s husband wants a reason to dump it. Looking at a tach while shifting is like looking at your feet while walking. Both make you a poor driver/walker. A race driver is concerned about that small rpm difference between getting maximum performance and a self destructing motor.
Second thought, I guess maybe an AVEO does fit that category.
I amend my remarks.
Is “lugging” an engine something that shortens an engine’s life - yes. However, what your husband is doing takes off so little engine life, you’ll never be able to measure the difference.
I’d even argue that your husband isn’t even causing any additional engine wear. If he is only “lightly” pressing on the accelerator while in “3rd gear by 20 mph”, he’s fine.
If I were you, I’d drop this. Supporting your spouse is far more important.
It will only produce that 200 HP at 5000 rpm if it is at full throttle. At half throttle, it will still spin 5000 rpm if the load permits, but it will not produce it’s full 200 HP. Horsepower is a combination of engine torque and engine speed, and can not be achieved without some of both.
No, the engine’s power is derived directly from the amount of gas it’s burning. It’s burning less gas at 1/2 throttle and 5000 rpm than it is at full throttle and 5000 rpm. That’s why a dyno has to put the engine under load. The power generated has to be absorbed by something.
You’re right, tachs should not be that necessary for driving, but good overall to measure engine performance.
I would LOVE to see the tach go away and the area replaced with more useful instruments (oil temp gauge, oil pressure gauge just to name a couple).
If you ask me, it’s not a good idea to support a spouse who will probably stubbornly stick to his ways, disregarding advice from more knowledgeable people and maybe wasting money in the process, but of course we’re getting way off track here now.
When to shift and “shifting wrong” is the subject. Wrong shifting is way,way down the list of things you can do or not do to your car that will cause damage. Damage comes from lack of maintenance or continued operation of a vehicle when it is malfunctioning.
Let me put it this way,lets say your engine reached the 250K milestone and needed a rebuild. Upon the disassembly the mechanic could not zero in on a feature and say “I see you have been shifting wrong”.
This is not about if I am right or if HE is right, it’s about the car. We don’t often buy a new car and he wants to “baby” it. My concern is about whether or not he is doing more damage by babying it, then by not. While it’s true that I am driven nuts by the way he drives, I am far more concerned about our investment then about telling him I am right.
Thank you to everyone for your advice!
We don’t often buy a new car and he wants to “baby” it.
This is fine. Please remember though that babying it means driving it as close to the recommended shift points and advice given in the owners manual and not what the driver thinks is best for the car. The people who made the car and wrote the manual are the experts.
Does anyone believe Jacksand and her husband will ever measure or detect shortened engine life due to the “3rd gear by 20 mph” style of driving?
Yes! No, it won’t cause a spectacular, catastrophic engine blow-up, but constantly short-shifting and forcing the engine to pull at too-low RPM does take a toll on the engine. It may not show for 60 or 80 thousand miles, but it will show in the form of excessively worn rings and bearings, and the consequent low compression and oil consumption. I’ve read about it and seen it!
I’m more concerned they’ll experience a shortened rear bumper from merging on freeways at 45 mph!
The OP said before “the engine does lug a little when he drives and there is very little accelerating power at all.” That seems to me to be an indicator that he isn’t shifting correctly.
I have a car with a different engine and different gearing, but I have it in third at 20 all the time, after making the adjustment I mentioned above. I get no sign of trouble and get swift and responsive acceleration. I usually accelerate gently and will shift at higher speeds when I need to accelerate faster or climb a hill. Each model is different, so you have to see how it acts to know if the method is incorrect.
I really don’t know if it will (or might) shorten engine life, but if the car doesn’t want to accelerate, I’d think something was wrong. Unless I was running the engine near the red line, I’d rather shift a few hundred RPMs high than a few hundred low.
Shifting early usually saves fuel (with all other factors being equal). Shifting at high RPMs usually uses more fuel.
The engine does lug a little when he drives and there is very little accelerating power at all.
This is the key information we needed. If the engine is lugging and it can barely accelerate, this is definitely bad for the engine. He needs to shift later.
Agreed. This is the definitive answer. Lugging the engine is bad for it. He should wait just a tad longer to shift.
When I was younger{pre 50 yrs old} I tried to convince friends and customers the proper way to shift a vehicle.
I came to the conclusion that I was wasting my time." Stupid is as stupid does." Good luck!