Manual gear question

I guess the gas you're burning is directly proportional to the engine spin number.
The faster it spins the faster you burn gas.

No, it doesn't particularly stress engine or transmission. Engine braking does though (the reverse of what you're trying to do). Staying in the middle of your powerband is generally correct because it allows you to change gears in either direction faster. However if you're looking to minimize fuel consumption then highest gear/lowest rpm is the way to go. Fourth for 30kph seems a bit excessive, though admittedly that depends on gear ratios.
Always low rev except for uphill roads.

Is anyone else just not very good at explaining manual to people? For me it's like
>Uhhh, yeah. When you do this, that happens and uhh. Making sense yet buddy?

I'm a terrible teacher because I learned manual purely through trial & error and can't really explain it in technical terms.

I thought I was stupid for not getting it.
In order for someone to get it, they must understand the leverage physics of transmission, otherwise it's just mumbo jumbo dumbo.

You don't need to understand anything to correctly use it, just practice. Literal 17 year old girls manage to drive it perfectly with little to no knowledge about the mechanics of it.

I've heard people say they shift down to overtake someone on the highway because it gives them more acceleration or something.

How does that work? Wouldn't it just cause you to slow down via engine braking?

You misunderstood.
I'm saying in order to "get it" you have to understand how transmission leverage work, you can obviously use it, I too did the same.

Like in math, you memorize formulas and can solve problems, you don't have to truly understand it.

You are supposed to push down the gas pedal a.k.a. accelerator after downshifting while overtaking.

Am I being baited? I cant tell, Im drunk.

That technique is 2 fast for you desu

No. 2 things happen when you downshift
>the engine spins faster, meaning it can flow more air, meaning it can burn more fuel, meaning it can make more power
This is very important. Have you ever noticed the car accelerates better once you get it revved up high?
>the reduced gearing gives the engine a greater mechanical advantage on the wheels
this doesn't have as big of an effect but it's still an important part of gear ratios on cars

If you dropped the revs, yes.

But if you downshift and keep the revs up (for example after downshift your revs double from 1500 to 3000) that puts you into the power and, rather than being out of it and trying to accelerate into it

yes and no, because at higher rpms you are making more HP = more speed

Let's say that you are in 5th gear at 90 km/hr at 2000 rpm, and you want to overtake a car in front so you shift down to 4th gear and the rpms will go from 2000 to 3000 or 3500 depending on gear ratios, and when you shift down it will decrease your speed at 80 km/hr but you'll be able to overtake faster in 4th than in 5th

>Am I being baited? I cant tell, Im drunk.
What's your drink of choice tonight sir?

I guess what I was saying is that I've been driving manual for 11 years and I still can't technically explain to a noob what's going on. I just kind of accept that "this" happens when I do "that" haha.

Not quite, he'll burn or waste more fuel if he stays in the higher gear to accelerate, so if he's in heavy traffic that's not maintaining a set speed its better to stay in a lower gear.

>My father says that I should not go on lower spins because it will hurt the engine.
This is false

>The faster it spins the faster you burn gas.
This is true

This has nothing to do with your (lack of) understanding of the physics of a manual gearbox. It has everything to do with your teaching skillss

>it can burn more fuel, meaning it can make more power
This is false

Doing 40 in 5th burns less fuel than doing 40 in 4th gear
So there's an equal amount of power but a different amount of fuel usage

Yes.

But you should get there quickly. Most fuel consumption comes from throttle position rather than engine speed. Staying in a lower gear as you build speed is more efficient. You should only change to your cruising gears relative to your speed once you reach it.

Higher gears give you better gas mileage. And it is better for your engine to be cruising at 1500 RPMs than to be on the interstate at 4000 RPMs for hours on end. As long as you don't lug your engine (giving it a lot of gas at low RPMs) than you will be fine. Just down shift when you need to accelerate.

>Most fuel consumption comes from throttle position rather than engine speed.
What did he mean by this.

he means flooring it in 4th to climb a hill is going to use more gas than shifting to 3rd and using 70% throttle

>better for your engine to be cruising at 1500 RPMs than to be on the interstate at 4000 RPMs for hours on end
I remember being annoyed when I "upgraded" from a '94 Civic to an '01. Really preferred the gearing and low seating position of the older one. My 2001 would cruise on the highway in 5th at like 3,300 RPM's. That drone at 75-80 was awful. I think the '94 would cruise at maybe 2,000 RPM's?

I don't think you understand what I'm saying. Your engine requires oxygen (air) to burn fuel. The more air it can flow, the more fuel it can burn. When you rev higher, you can flow more air at WOT than low revs at WOT. That means you can burn more fuel and make more power.
I'm not comparing fuel efficiency at different vehicle speeds. I'm comparing power at different engine speeds.

^^^ Maybe 2,500 RPM's actually ^^^

Still way more tolerable.

>Theoretically I burn less gas because of less engine spins per minute, right?
If the throttle is constant then yes. Buy if you need to apply more throttle in a higher gear then maybe not.
Your engine is most efficient at peak torque, so find that and try to get close to it.

did you change from a 5-speed to 4-speed?

1. Yes, that's common sense.
2. It depends. The older WRX and WRX STi comes to mind with this one. If you get into boost in to high of a gear or to low RPM, the stock tune makes the car run stupid rich and can lead damage the ringlands. No idea if Subaru ironed this out in the newer models, though. With something N/A like an S2000 or a stock Mustang, you'll just have slow acceleration and maybe uncomfortable lugging.

Just stay in the appropriate gear but have good throttle control.
Unless you're crusing you always want to have power available just in case

No, the '94 and '01 were both manual 5-speeds. The '01 is just geared differently so it cruises at a higher RPM. Somewhere around 3,300 while the '94 was maybe 2,500. As a result, the older Civic got better MPG's and had less drone at highway speeds.

Really only got the new one because I fucked up the '94 drunk driving and my dad offered $3k for his '01.

How can this be so hard to understand for some people? Isn't it really just common sense?

I mean, you can feel when an engine is struggling. And you can feel when an engine is too high up in the RPM range to drive comfortably at a given speed.

How much common sense must one lack to have to really actively think about this while driving?

>The older WRX and WRX STi comes to mind with this one. If you get into boost in to high of a gear or to low RPM, the stock tune makes the car run stupid rich and can lead damage the ringlands. No idea if Subaru ironed this out in the newer models, though.
Citation needed.

Not necessarily. You seem to thing fuel rate and RPM are directly linked. They're not.
If you require just as much throttle to maintain a higher gear at a constant speed, then fuel usage will be identical regardless of RPM.
This 100%.

how do you know when you should drop a gear or not based on rpms then?

Like if there's a slight incline coming up but it's so obvious that you should drop a gear, how do you know if it's better to just push the throttle a bit and keep the rpms low, or if you should drop a gear and raise the rpms by a 1000.

It's widely known. You've either never owned a Subaru or are a 17 year old who slapped on an intake and a downpipe and fucked the car by not tuning for the mods.

Because throttle by wire is a thing for every car by now so how do you really know if the throttle is just not responding or it's adjusting automatically for you.

Get a feel for your car. If you know it'll require more throttle to maintain a higher gear than it would changing down, that'd be where it's beneficial down changing.
Every car's different, so feel is the only real correct answer here.

Neither. I own an 04 Sti. No problems.

I don't know what to tell you man. Unequal length headers(directly responsible for poor exhaust scavenging), building boost in to high of a gear/low RPM, and poor factory tunes have been linking to ringland failure in earlier model WRX and STis.

I'm happy to hear that your car is healthy, but you need to educate yourself on the common issues with these cars.

Not him, but the EJ25 is notorious for having a bad factory tune, fourth cylinder is the one that always goes.

It's true but depends on the throttle input. If you are engine braking down a hill and at 3500rpm you're still not using any gas.

Depends entirely on the car, this is bait intended or not, and since your English is broken you live in EU and should already know how to drive "manual gear".

Building boost in high gear on any gasoline turbo engine is a bad idea.

But in a horizontally opposed engine, it is especially bad.

Exactly, thank you.

>1. Can you save gas by putting high gear in slower speeds (less engine "spins")
If it's not lugging and you're not accelerating, yes. Ideally you'd cruise in the highest gear you can without lugging and downshift to speed up.
>2.Does that hurt the engine or the transmission?
If you lug it, yes, badly. You'll know you're doing this when you have no power in your current gear and the car is shaking and trying to stall

Anytime, love these goofy-fuck cars.

are the revs that a car stalls at different for each car? how would I know my stall point?
would they also be different stall revs for different gears?
t. automatic driver

>are the revs that a car stalls at different for each car?
very different. And it also depends on applied load too.

Completely depends on the car. 4 bangers will generally rev higher because no power.

Lugging the engine is not good. That's when you're close to stalling and the engine is making a luggish noise.

Having a higher rpm allows for more efficient burn of fuel, and prevents knock from occuring.

If your car is fuel injected and has VVT (variable valve timing) then you shouldn't worry about high rpms. On my 4-cylinder I can still get 25-30 mpg just cruising even at 4000 rpm.

>how would I know my stall point?
by driving the car and learning how it responds. It sounds like you haven't driven manual before. You'll pick it up quickly. I remember I overthought things like that before I learned.