Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Help my friend and I settle this argument

today my friend and i were having a discussion and we ended up getting into a disagreement about manual cars. here’s the scenario:

when on a hill, we discussed the possibilty that it might be easier to make it down the hill if you simply put the car to neutral and let it roll, using the brake to adjust your speed; however, i told my friend that if you did that, you would have to engage the clutch until you reached the bottom of the hill…he disagreed. who’s right and why?

the wager is a 6 pack of yeulings…

While coasting down a steep hill is unsafe for a variety of reasons, re-engaging the transmission into high gear near the bottom shouldn’t be a problem. Re-engaging into a lower gear might require double de-clutching, matching your engine’s RPM to that of its speed in the lower gear. Is that your question?

First, coasting in neutral is unsafe. You can easily overheat the brakes if you use them going down a long hill. You are better off leaving it in gear so the momentum of the car is powering the accessories and you maintain control.

The answer to your question is that there is no reason to hold the clutch in while the shifter is in neutral. When you put it into gear again, you can press the clutch right before you shift into gear. So your friend is right. There is no reason to hold the clutch in until you get to the bottom of the hill. In fact, there is no legitimate reason to shift to neutral either, but in either case, you are wrong and your friend is right.

You don’t say what kind of car it is, but unless it is a tactor trailer, you only need to press the clutch and shift into gear. What MG McAnick said about double-clutching only applies to tractor trailers because their transmissions don’t have synchronizers like a car manual transmission has.

I will add that with many newer cars, you will save more fuel by leaving it in gear, even if you need to put it in gear before you reach the bottom.

As said, the more important part is the safety factor. Don’t drive down a hill in neutral, it can cause several serious safety problems.

Sorry Whitey, I was thinking of my MGs with their weak synchros. Double de-clutching out of Georgia overdrive always worked for me.

Setting aside the fact that it would be an unsafe act, and assuming that you’re driving a manual transmission, once the car is in neutral you can take your foot off of the clutch.

You’ve disengaged the clutch by shifting into neutral so you don’t need to keep your foot on the pedal.

The car in question should be left in a low gear when going down-hill. This is what is beautiful about driving a stick: Engine braking! It’s dangerous and illegal to coast in neutral and it’s obnoxious to ride your brakes like that. So i’d say you are right.

Other than this coasting down hills, what do you doin your spare time?

Thanks guys. It was merely a hypothetical. I should have clarified more…putting aside the safety issues…thinking about it more in a vaccuum, if you will, was the only point. Trust me, no one I know of is going to do or try this…it was more one of “what if” situations. The safety ramifications alone (along with the fact that is horrible for the brakes)…its obvious such a thing should never be done. I’m sorry I didn’t clarify in the first place.

I think you were clear enough in your post.

But I also believe that you owe your friend a six-pack.

Ditto to all of the above excellent answers.

From the owners manual for my wifes 02 Sonata:

"Dont ride the brakes, this can overheat the brakes & cause them to malfunction. Instead when you are driving down a long hill, shift to a lower gear. When you do this engine braking will help slow the car.

As is so often the case a quick look at your owners manual will have the info you need.

Thanks again for your help! And yes, I do owe my friend a six pack…

NO, you do need to clarify your question. What does, “…make it easier to make it down the hill…” mean? Easier for what, or, for whom?

ok, so what manifested the conversation that brought about the disagreement goes back to a discussion about one’s level of proficiency while driving a standard. as you know, driving a manual on level terrain is relatively easy when compared to driving through hills and mountains. so for a person that has some difficulty there…hypothetically (putting aside all the pros and cons), if that person decided to simply “coast” down the hill, would it be easier for them to put the car in neutral and roll down that hill…and if they did, if the clutch would need to be engaged or not (which is the more important question). the answers already supplied have sufficiently addressed the situation i have laid out…as a result, i owe my friend some beer.

now, for those that are making more out of this than is necessary, in addition to the pros and cons already brought up, i know someone is going to read too far into it and say well, if someone isn’t proficient with a manual, they shouldn’t be driving up and down hills or at all…which, for the sake of the spirit of this discussion, would be irrelevant.

To put it bluntly, your question doesn’t make any sense. So, flip a coin for who buys the beer.

I’m curious about this. When I drive down a long hill in gear, I’m riding the brakes the whole time, so how would coasting be different? And why would keeping it in gear use less gas? That doesn’t make any sense to me. Thanks, I know nothing about cars, so appreciate the info.

If I understand the question correctly, you’re asking whether it matters whether the clutch pedal is in or out while you’re coasting down the hill in neutral?

It does not matter. Once you put the tranny in neutral you are completely removing the ability of the clutch assembly to connect the engine to the wheels. Your engine and wheels are completely free of one another regardless of the position of the clutch pedal. Your car is free rolling.

Now I think you owe us a 6 pack of yeulings…

Some modern fuel injected engines cut off fuel when coasting in gear since the car’s momentum can keep the car running. With these particular cars (don’t ask me which ones they are), costing in neurtal means the engine needs to use fuel to keep the engine running.

When you drive down long hills, you should not ride the brakes. They could overheat and the brake fluid could boil, leading to complete brake failure. If you are lucky, the brakes will simply heat up and not work as well. The best technique for going down long steep hills is to put the car in a gear that is low enough that the engine will control your speed without you having to use the brakes. So if you are riding the brakes in gear going down a long hill, try shifting to a lower gear, even if you are driving an automatic. The engine may get a little louder, but it should not harm the car.

Some truck drivers use a technique called stab braking, where you use the brakes to slow down, let the truck pick up speed, and you use the brakes to bring it back down again, keeping the truck within a particular speed range the whole time. This is only a good idea in a truck if you find yourself going down a hill in the wrong gear. In a car, you can do this to bring your speed down and then shift into a gear that is now enough to control your speed.

Some modern cars will totally shut off the fuel supply when the accelerator is not being depressed and the car is turning the engine over (due to momentum or going down hill) faster than idle. So with my car that idles at 1,200 rpm is going down a hill in gear and I am not pressing on the accelerator, then the computer shuts off all fuel to the engine I am getting miles with no fuel usage. If I were to take it out of gear, I would go faster, but I would also be using fuel.