Some Hypermiling questions
 

I recently purchased a manual transmission car, and have a few questions on how to increase its fuel efficiency even greater. This is my first time driving stick shift (aside from a motorcycle), so I was wondering what would be the best time to shift gears (in rpm's) in order to keep efficiency up. Its a '93 Civic Dx if that helps. One more question. Lets say I'm coasting in neutral at 30 mph, and need to accelerate because the streetlight turned green. Would I shift to the appropriate gear for that speed? And would going from neutral to 3rd, for example, damage the transmission? Any answers would be greatly appreciated, since I'm only a beginner! I've been hypermiling in automatic cars though, and have seen some impressive gains, like 20% mpg, so I'm optimistic! Thanks again

couldn't tell you the RPM's to shift at, the last time i owned a honda it was turbocharged and i made good use of it. as far as the shift from neutral to 3rd (or whatever gear you're going to) make sure you "blip" the throttle to raise engine RPM prior to engaging the clutch (a process called "rev matching") it could take some time to figure out exactly how high you want to rev your engine prior to engaging the clutch, it's all practice.

I would start by reading the owners manuel, if you didn't get one with the car find one and read it.

Traditionally, Belgian beginners were told to shift up at 20, 40, 60 and 80-90 kph.
That's 12.5 , 25, 37.5 and 50-56 mph.
Because the gearing is normally adjusted to the engine's power, this works pretty well for just about every manual car regardless of displacement or fuel type.
That's the traditional way, but it'll get you started fine.

The more ecological way is to shift earlier and accelerate at lower rpm and higher engine loading (which gives better specific fuel consumption).
Beginners are now taught to short-shift up around 2500rpm in gasoline cars - and 2000rpm on diesels.

There's plenty of hypermilers with Civics of that generation.
They'll be short-shifting as well ;)

You'll hear and feel it when you're lugging the engine, so do some experimenting on quiet roads to see at what speeds / rpm it happens in the different gears, then avoid going that low in the rpm range when the engine has to work.


1st gear is there to get you going and for very slow speed manoeuvring only.
1st is a wildly inefficient gear.
In slow moving traffic that's too slow for steadily using 2nd, don't change down into 1st, but briefly pulse in 2nd and then push in the clutch again to glide. Try to keep it rolling, and repeat when required.


Shift into 2nd right after getting going.
I shift into 2nd within about 2 car lengths from a stop.
Some people skip 1st altogether, and start going in 2nd.

Try to always be in the highest gear the engine will cope with, for the speed you're driving.

Coming down from higher speed to a lower constant speed, or on slight downhills, try to stay in a higher gear than you normally would. You can often get away with it without lugging the engine, when you're just rolling along and the engine is very lightly loaded.
It'll work well for FE - until you need to accelerate again or have to deal with a slight incline, and the higher gear can't pull off the low rpm anymore so you'll need to change down 1 or even 2 gears.


Shift into the appropriate gear for the speed you're doing.

If the speed is near the upper end of the speed range for a gear, switch to the higher gear right away - it'll be a lot smoother without feathering out the clutch for a long time.

Help the engine to get up to speed by rev-matching it with a bit of throttle while you're re-engaging the clutch.

It won't if you disengage the clutch fully - so make sure to push it in all the way, then shift into gear and smoothly re-engage the clutch.

At 30mph, you're probably OK to shift into 4th already.


A note on using the clutch :

Beginning stick-shifters have a tendency to use the clutch to control speed.
This is only done when manoeuvring at very low speeds in 1st and reverse, when a fully engaged clutch would give excessive speeds.

Other than that, the clutch is only briefly and smoothly used to get rolling, and to shift gears.

However, some hypermilers will use the clutch to bump-start their engine after coasting with the engine shut off . That's pretty advanced hypermiling.

Other than these conditions, the clutch should be either fully engaged, or fully disengaged. Clutch slippage = wear, and should be reduced to a minimum.


On a manual tranny, there's no slush box to compensate anything, and no slippage unless you use the clutch, so you have to be smooth with the expensive foot.

Train yourself to use the accelerator smoothly, so you can smoothly accelerate away from idle to higher rpm, then slow down smoothly to rolling in idle again without any jerking or bucking - all while staying in the same gear and without using the clutch.
Only when you can do that in 1st, are you really controlling your right foot ;)

Wow, that is a lot of info to process! I'm gonna start learning to drive on Thursday so I'll post up how it goes, thanks for the tips

I never rev matched on any car I drove, gasoline or diesel, and never heard about it before reading hypermiling forums.

Is it how old cars (older than late 70's) had to be driven or is it an hypermiling trick ?

May be when decelerating as the rev after the down shift is higher than before; noticeably when racing as the rev will be as high as possible to have more engine brake.

In fact the single time I hear about rev matching is when you want to drive a manual and the clutch doesn't work anymore...

TIA,

Denis.

Just take it easy in the beginning.

Sit in the car, handbrake on, and do some dry shifts with the engine off.
That way, you'll get an idea of where the stick is relative to the gear you're in, without looking, just by feel.

When driving, if anything goes not as you'd want it to - lurching, bucking, slowing down too fast - push in the clutch, and check the gear you're in ;)

Never push or pull hard on the stick.
If the gearbox and clutch are OK, it'll shift smoothly and won't require force.
If it won't go into gear, put it in neutral, release the clutch, push it back in, and try that gear again.

Shifting into reverse : only when fully stopped.
Downshifting into first : only at very low speeds , say < 6mph

I've been doing that since I learned to drive in the late 1980s.

You're doing it when shifting up, but probably don't realize it ;)

It uses gas, so it's not really a hypermiling trick.
It keeps you from slowing down much though, if you just want to get into a lower gear.
It also reduces wear on the clutch plates, as you reduce their relative speeds when coupling them.

It is not much different from riding you motorcycle you are just using your feet when letting out the clutch in first on a bike you get that sweet spot ... same thing on a car car is easier than a bike in my opinion. Don't stress it, drive proper before trying to hypermill, there is no one set rpm to shift at each engine has its own area of power I can short shift a chevy v8 at 2000 rpm and get to speed steady or bring it to 3,000 for a much faster run but it all depends if I am driving a 3spd 4spd 5spd or a 6spd transmission and what the gearing is.

A new clutch pressure plate and throw out bearing costs a whole heck more than a tank of gas.

I'll weigh in this. My next-gen DX should be similar in gear ratios and engine power to yours.

Here's how I handle my shifts. You can shift even sooner but these are close enough and easy to remember.

1st: just enough to get rolling for a few seconds. This gear gobbles gas so get out of it.
2nd: up to 20 mph
3rd: up to 30 mph
4th: up to 40 mph
5th: anything above that

I've never really heard the term much outside of hypermilers and riceboys. Hypermilers have to rev match because they're going into gear from neutral so much, while riceboys think it makes them sound more 1337 than simply saying "downshifting." But you've either been rev matching every shift or you've been using your clutch as a very expensive brake pad. It's something you automatically do when shifting normally, but it takes a lot of focus when hypermiling. There's no intuitive "just a little bit" of gas you can give it to match revs when you've been coasting at 800 RPM for the last minute. Now you need to watch your speed and figure out where you need to put your revs to get into the gear you're looking for.

I believe the 5th and 6th gen DXs and LXs were nearly identical for gears and power, my parent's have a 94' LX that drives almost exactly like my 97', except that the clutch engages earlier (I was used to only pushing the 97's clutch halfway to shift).

Those are the speeds for acceleration, if you are cruising on flat or slightly downhill ground, you should be able to use the next higher gear (like at 35, I usually shift to 5th if I know I won't be needing any power soon).

But Fat Charlie, what about the role of the synchronizers?

I'm awful at rev matching. Takes me too long. I want to get better at it though.

Edit: Takes too long when I'm trying to rev match a downshift, not when trying to rev match from N to a gear (although I only occasionally do it).

That's true. Those gear shifts are for acceleration. I exclusively drive pulse & glide so that's all I'm ever doing. If you're willing to do the work, it's the most fuel-efficient way to drive.

For steady speed, use the highest gear that can maintain speed. My car can do that in 5th as low as 25 mph.

The synchros let you engage gears without grenading the whole box. Now that the gears are all meshed and doing turns for 40 MPH, your crankshaft is still spinning at idle. You need to bring your engine revs up to match what your transmission is doing or your clutch will have to do it for you, acting as a big, expensive brake pad.

Rev matching coming out of a glide can't take too long. Except for an emergency it should be pretty well planned- you've got your whole glide to think about it. Pick your re-engage speed before you decelerate to it and work to meet it: I'm decelerating pretty quickly through 40 so I have to get ready. I'm going to jump back in at 30 and I want to be in 3rd gear for a quick, strong pulse so I need to be at about 2500 RPM. And... go!

Ah, okay. I didn't realize that.

Every heard of the abbreviated method, in which you simply clutch-in, downshift the gear shifter, and blip the throttle (rather than going into neutral) before letting the clutch out?

Is this method inadequate? It must be inferior somehow, or who would do it the typical (longer) way?

Okay, what you're thinking of is "double clutching." I've never driven an unsynchronized manual, so I've never had to do it. That's where you go fully into neutral, rev match then hit the clutch again and shift into gear.

With a synchronized gearbox you just shift normally (your abbreviated method). Upshifting you match revs without trying because the engine slows when you lift off the throttle and hit the clutch. Downshifting you match with that throttle blip. It's almost as easy as on the upshift, but it does take a little more involvement on your part.

We are trying to help a raw beginner here! The advanced stuff might be a bit much at first.

My daily driver is an '87 Honda CRX. 1st gear just to get you rolling...2nd to 3rd at around 15mph...into 4th 22-25mphish.... into 5th by 30mph on downhill or level roads, if I'm slightly accelerating to approach a slight hill, I might wait on 5th until 35mph.

You are on your own on hills... from your motorcycle, just remember not to let it bog down. For the most part....forget about downshifting... go into neutral.. practice coasting toward stoplights, and signs, as much as following traffic will allow. You MUST learn to MIRROR DRIVE alot to help yourself set up your next best move!

Try to find good 30-45mph. roads in your area to take that have the fewest stop/light/signs... just work on being Smooooooth!!!

Try to use the brakes hardly at all.... anticipate traffic problems ahead, so you are never surprised into having to brake hard.

rpms.... most of my upshifting is between 1,200 and 1,500...very mello. If you commute in a busy place during rush hrs, people behind you aren't going to appreciate your econo efforts! Be ready to back off perfection, or grow a hard turtle shell.

Don't go over 50-55mph anywhere if you can help it.

Think about bumping up your tires to maybe 5-7 psi above what the sidewall cold max. says on the tire. That's not too much to ride real rough, or wear the tires out too fast. It does mean to remember common sense to NOW go into wet corners a little slower than you used to....my latest idea for a bumper sticker would be this: Friends don't let friends do LATERAL SCRUB!!

Have fun and practice, practice, practice!!!!! Never use the clutch like a brake!!

Sometimes Im in 4th by 15 and 5th by 25. But then again my power/weight ratio is a bit excessive, and I dont get the MPG a stock car gets either...

I usually shift at 1200 RPM.

Sure.
Why would it be inadequate ?
I don't suppose you're still driving around with an unsynchronized gearbox ?

Quoted for context. Larry's CRX below is a good comparison. His advice is spot-on and worth repeating.

JohnnyRun, sorry for highjacking your thread with rev-matching questions. I feel bad, so I'll stop asking questions in your thread after I explain my line of thinking below.

Nah, synchronized gear box. It just made me think: "who would double clutch if rev matching (clutch in, blip throttle etc. - the method I called 'abbreviated') does the job?" I guess that's the answer: if there are no synchros.

--

JohnnyRun your stick driving practice was Thursday, right? How did it go for you?

Unfortunately I wasn't able to drive it, but I will soon. And no worries about asking questions on my posts, the more you ask the more I learn!

I'm in a similar position as you. 12 years as a biker, 2 months as the owner of a stick (2005 Mustang GT).

Drive it like your bike. You'd never dump it into 1st going 75 on the bike, so the same applies to your car. Like others have said, pick the right gear for your speed. Like the bike, you will know just by the sound of your engine, so give it some time.

Once you get used to the feel of the engine and your gear ratios, you will be able to dump it into a higher gear. In your example, you're in neutral at 30 MPH and need to go into gear. Because of my gearing in my Mustang, I can put it into 5th gear at 30 MPH (and be just above idle at ~949 RPM). Acceleration will be slow, but I'll most likely be catching up to the cars that were stopped at the light. If there were no cars ahead, I'd dump it into 4th and get up to speed and shift normally, assuming the speed limit is higher than 30, otherwise I'd just stay in 5th.