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Clutch in a gasoline car VS Clutch in a Diesel car

I have actually gotten pretty good at engaging the clutch on an idling engine without stalling the engine in a gasoline powered car. It’s great clutch engagement practice.
I also try my best never to come to a complete dead stop at intersections. Braking early so I can slowly approach the red light at walking speed instead of racing to the red light and making a complete dead stop. That way, when the light turns green, I can restart by just letting the clutch out on an idling engine with zero clutch wear, usually racing past the people who ran up to the red light and made a complete dead stop. It’s amazing what a little momentum can do, the drag racers call this a “hole shot” and it’s why they try to stage as shallow as possible, so they can already be in motion before the light turns green and their front wheels break the light beam that senses a premature start.
Anyone can engage the clutch on a idling diesel because a diesel’s idle governor automatically “opens the throttle” in response to the rpm dropping, and doing so wears the clutch the least.

Here’s what I find interesting . . . and amusing, to an extent

Opinion seems to be evenly divided

Half the regulars say the driving instructor is an idiot

Half the regulars say the driving instructor is correct

The driving instructor could be both correct and an idiot.

I suggest studying the difference between being wrong, misinformed, or mistaken and being a moron.
Calling those who disagree with you a “moron” or “idiot” is insulting and most of the real life people I ever knew that thought that way were themselves know-it-alls more full of dogma than understanding.

I see it as the difference between ‘can’ and ‘should’. Can I engage the diesel’s clutch with no throttle? Sure. Should I only engage it that way? Not in my opinion.

Like most things the answer is usually yes-both. Now ask something like if Romex should be put in conduit and watch the response.

I believe it depends on the situation and the design of the transmission itself. Some vehicles are blessed with lower first and reverse gears than others.

True, but the instructor said it was wrong to use any throttle. That is incorrect.

I was waiting behind another car at a red light on a slight uphill. When the light turned green, the driver in front of me stalled while I got rolling with less than 1000 on the tach, changed lanes and kept going. BTW, i was driving a 1.5 liter low torque subcompact. If someone is going slower than your liking, trying using the steering wheel to go around. Pulling someone from their car makes you even slower


Sounds like you were driving a Yaris or Tercel . . . ?

I have a Tercel in my driveway. It’s the spare car, but it actually gets driven about 2 or 3 days of the week.

Every once in awhile, I’ll get surprised looks, because I can actually keep up with traffic, and don’t slow anybody else down. Except for those guys that want to do 55-60 in a 35 . . . pretty much everybody slows them down

I have never driven a diesel car with a manual transmission. I can see where a diesel might have more torque at lower rpm’s compared to a similar sized gas engine. I also wonder if a diesel has a higher idle rpm compared to a gas engine. The driving instructor might offer good advice on flat road surfaces, but there must be situations (ie. starting on an uphill incline) where giving some throttle to a diesel engine is needed. Therefore I think a new driver needs to be able to do either technique.

I don’t believe the OP did any harm to his diesel powered car and that his clutch will have a long and useful life.

Part of the beauty of driving, and one of the problems with developing “self driving” cars, is there are just so many situations you encounter that you have to engage your brain and adjust as needed.

OK, pet peeve or at least a small one, you’re behind a guy with a manual at a light with cars behind. When the light changes you take off and try not to do the caterpillar thing. Then when the guy goes to shift to 2nd, it takes him a while and the car slows way down again and you just about have to brake. Not following too close because you’re just off the light. I think if people are going to insist on buying a manual transmission, they ought to at least learn to shift.

@db, close enough of a guess. It was my ECHO based scion xb. I’ve driven the Tercel and that was a great little car. Slick shifter, mechanical steering feel, and planted around corners. The entire car was way more fun than that little engine

First of all, we, the tripedal luddites, aren’t slowing down noticeably during our 1-2 shifts. We simply disconnected the wheels from the engine so we aren’t speeding up. The only forces slowing us down are rolling friction and the miniscule air drag, if we aren’t accelerating on a hill. To us, it’s the other drivers who don’t notice our cars getting bigger and bigger as we coast during our 1-2 shifts

Secondly, I’m driving properly. I’m waiting for the engine to wind down until its speed matches that of second gear. I’m doing it this way because I want to minimize wear to the clutch plate, shock to the rest of the car, and bobbing passenger heads

Realize that we all have to learn sometime, and it’s possible that the person in front of you may be a learner.
I’m a quadrupedal luddite. Except when I’m sober. Then I’m a biped. :smile:

How many people were on that plane that ditched in the Hudson river? Lucky for them their pilot was capable of cancelling the auto pilot function and flying “by the seat of his pants,” making split second decisions in the face of such a desperate situation.

I’ve done more reading as well as read all of your posts and spoken with the professor.
With regards to my question, I think keith said it best:

I agree with your wife’s instructor as to not needing to give it gas, but I also don’t think you are doing any significant damage by giving it a little throttle. It does not matter whether its a gas engine or a diesel, the more throttle you give it, the harder it is on the clutch. The damage or wear increases exponentially though, a little extra throttle, very minimal damage, a little more throttle will add more wear, full throttle all the time, the clutch will wear out much quicker.

In other words, lets say that 5% throttle takes 0.000001" off the plate, 10% throttle might take 0.0000015", 20% throttle might take 0.000005", 50% might go 0.0001" and 100% might take 0.001" per launch. Clutch wear goes up faster than the % throttle.

Just goes to show, you learn something every day!

This is a great forum you guys have here.
Thanks for helping me with this little crisis.