Hypermiling

[Roger1]

Hey all!
I've been reading the threads about gas prices, and "how many MPG do you get? Shecky posted a link about hypermilers. For those of you who don't know, these are people who go to rediculous ends to eke out the last mile from a gallon of gas. I thought this was pretty cool for the most part. So I decided I would try a little "hypermiling" myself. I'm not going to go to the extremes these people do (something about drafting a few inches from the back end of a semi makes me nervous).

Anyway, I will drive the speed limit, do some drafting behind semis (several car lengths, of course), and turn off my car when driving down hills. I will also forgo A/C if it gets hot, and drive with the windows up. I currently get 36-39 miles per gallon. I will start tomorrow morning, when I fill up my gas tank. Normally, I am just under 200 miles at the 1/2 tank mark. I will let you know how I'm doing later in the week.


Link:http://www.hypermiling.com/

 

[CanadaRAM]

and turn off my car when driving down hills.

Note> that this is not legal in some jurisdictions - and can be downright dangerous in cars with power brakes and steering.

 

[pseudobrit]

Hey all!
I've been reading the threads about gas prices, and "how many MPG do you get? Shecky posted a link about hypermilers. For those of you who don't know, these are people who go to rediculous ends to eke out the last mile from a gallon of gas. I thought this was pretty cool for the most part. So I decided I would try a little "hypermiling" myself. I'm not going to go to the extremes these people do (something about drafting a few inches from the back end of a semi makes me nervous).

Anyway, I will drive the speed limit, do some drafting behind semis (several car lengths, of course), and turn off my car when driving down hills. I will also forgo A/C if it gets hot, and drive with the windows up. I currently get 36-39 miles per gallon. I will start tomorrow morning, when I fill up my gas tank. Normally, I am just under 200 miles at the 1/2 tank mark. I will let you know how I'm doing later in the week.


Link:http://www.hypermiling.com/

Some of that stuff is nuts, and the rest is common sense.

It's best to know what the torque map of your engine looks like. Then try to keep the motor in the lowest gear possible while maintaining a reasonable level of torque.

When I'm in gear and my foot is off the accelerator the ECU asks for 0mg of fuel delivery. Of course since my crankshaft is still turning and my car is still on I have vacuum for the brake and steering servos, and won't cause an accident if I have to stop or manoevre suddenly. And I won't kill my starter by using it twice a mile.

Turning off the car while travelling downhill is madness.
Driving closely behind a semi gets your windshield cracked.

 

[nickster9224]

i dont see how it save gas turining it off down hills, when you use a signifigant amount of gas starting your car

 

[pseudobrit]

i dont see how it save gas turining it off down hills, when you use a signifigant amount of gas starting your car

Even if it doesn't it's dangerous and murder on your starter.

I have a sixth sense for fuel savings using inertia and conservative braking/acceleration from bicycling, where a touch of the brakes bleeds off speed that (eventually) is only won back by physical exertion. When it's literally a pain to overcome inefficient habits on a bike, you learn quickly.

 

[Counterfit]

Some of that stuff is nuts, and the rest is common sense.

It's best to know what the torque map of your engine looks like. Then try to keep the motor in the lowest gear possible while maintaining a reasonable level of torque.

I think you mean highest. Everyone messes that up. 1st = short (low) 5th/6th = tall (high). But the point is the same, pick the highest gear you can to keep the revs lower.

Turning off the car while travelling downhill is madness.

Agreed. In my state, even being in neutral is illegal.

Driving closely behind a semi gets your windshield cracked.

If you're close enough, your radiator gets hit first.

 

[mkrishnan]

When I'm in gear and my foot is off the accelerator the ECU asks for 0mg of fuel delivery.

Is this technically correct? Isn't the minimal fuel delivered by the injectors always enough to make the cylinders fire, at the least (or are you talking about a vehicle that uses a non-standard engine cycle?)? I don't think the fuel delivery ever goes to true zero while the engine is turning.

 

[Roger1]

I think you mean highest. Everyone messes that up. 1st = short (low) 5th/6th = tall (high). But the point is the same, pick the highest gear you can to keep the revs lower.



Agreed. In my state, even being in neutral is illegal.



If you're close enough, your radiator gets hit first.

I try doing the gear thing, and it works some, so I will continue doing it. As for going down hill with the engine off, I don't have any really BIG hills, so I figured I'd try it. If I lived in Colorado or somewhere, probably not. As for being close to semis, again, not TOO close. Several car lengths, at least.

Edit: I won't be doing a lot of this stuff with other traffic around (downhill coasting, etc) because this IS Michigan, and the speed limit seems to be more of a suggestion than a law

 

[pseudobrit]

I think you mean highest. Everyone messes that up. 1st = short (low) 5th/6th = tall (high). But the point is the same, pick the highest gear you can to keep the revs lower.

Whoops, that's my oversight. I was indeed thinking about low revs while writing about the gears.

 

[pseudobrit]

Is this technically correct? Isn't the minimal fuel delivered by the injectors always enough to make the cylinders fire, at the least (or are you talking about a vehicle that uses a non-standard engine cycle?)? I don't think the fuel delivery ever goes to true zero while the engine is turning.

I don't know if you'd call it non-standard, but it's a direct injection diesel cycle. The computer cuts off fuel injection on engine overrun.

 

[twoodcc]

i actually started doing this (or some of it) after reading the link for the other thread.

my overall average before trying this was just over 23 mpg in my tacoma, and i got 27.7 when i filled up yesterday . but basically i just use cruise control on the freeway (well basically any road that i can) and keep it below 60 mph (i got the best at like 52 mph, so i'm guessing the lower the better, since my truck sits up higher and therefore more wind resistance)

and i also have a scangauge2 in my truck, so that helps me monitor my mpg

i do coast, but i don't turn off the truck. and it's a manual

 

[SkyBell]

i dont see how it save gas turining it off down hills, when you use a signifigant amount of gas starting your car

Actually, it's suggested that you turn off your car if you are going to be idleing for more then 10 seconds (unless you are at a stoplight, of course) Because in most cases, 10 seconds of idleing is how much gas it takes to start your car.

 

[Bill Gates]

Actually, it's suggested that you turn off your car if you are going to be idleing for more then 10 seconds (unless you are at a stoplight, of course) Because in most cases, 10 seconds of idleing is how much gas it takes to start your car.

However, that can be just as bad overall as letting it idle. When you first start your car, you have no oil pressure. The second it takes to build oil pressure is when a lot of wear and tear occurs. Not to mention wear on the starter and battery. I live by the 5 or so minute rule instead of 10 seconds due to this.

 

[Abstract]

Note> that this is not legal in some jurisdictions - and can be downright dangerous in cars with power brakes and steering.

I can't even do that in my car. I can't restart my car unless I'm in park (P).

 

[iGav]

Anyway, I will drive the speed limit, do some drafting behind semis (several car lengths, of course), and turn off my car when driving down hills. I will also forgo A/C if it gets hot, and drive with the windows up. I currently get 36-39 miles per gallon. I will start tomorrow morning, when I fill up my gas tank. Normally, I am just under 200 miles at the 1/2 tank mark. I will let you know how I'm doing later in the week.

Don't forget to fold in the wing mirrors and remove the front and rear windows.

 

[Roger1]

Don't forget to fold in the wing mirrors and remove the front and rear windows.

They're power mirrors. It would take too much energy to take them off. At least as much as it would to wash the car

Anyway, I started this morning, just trying to do the speed limit. It's amazing how many cars line up behind you doing 55 mph (in a 55 zone). It's difficult trying to stay at the speed limit while they are doing that.

Anywho, time to start work.

 

[iGav]

Anyway, I started this morning, just trying to do the speed limit. It's amazing how many cars line up behind you doing 55 mph (in a 55 zone). It's difficult trying to stay at the speed limit while they are doing that.

If you really wanted to make a difference... use sellotape to tape up the panel and shut lines.

Fit economy run-flats, this way you'll also shed weight by not requiring a spare, and all the associated ancillaries.

Run your tyres several psi higher to reduce rolling resistance.

Only fill up with enough petrol to cover your journey. Don't brim it.

Remove mudflaps/guards for the summer months.

 

[takao]

don't shut off the engine while driving downhill, especially in newer cars with power assisted steering and braking
shutting off AC can be a big gas safer though: around 10% as far as i remember

 

[mkrishnan]

I don't know if you'd call it non-standard, but it's a direct injection diesel cycle. The computer cuts off fuel injection on engine overrun.

Ahhh, sorry, for diesel, that makes sense. I thought you were talking about gasoline / petroleum.

 

[twoodcc]

Anyway, I started this morning, just trying to do the speed limit. It's amazing how many cars line up behind you doing 55 mph (in a 55 zone). It's difficult trying to stay at the speed limit while they are doing that.

Anywho, time to start work.

don't give in to them! if you want to drive 55 in a 55, then do it

 

[pseudobrit]

If you really wanted to make a difference... use sellotape to tape up the panel and shut lines.

Fit economy run-flats, this way you'll also shed weight by not requiring a spare, and all the associated ancillaries.

Run your tyres several psi higher to reduce rolling resistance.

Only fill up with enough petrol to cover your journey. Don't brim it.

Remove mudflaps/guards for the summer months.

Don't forget fender skirts.

 

[yg17]

I get low 20s city and high 20s highway, and have decided that getting more out isn't worth it. The cost is negligible, and I like being comfortable while driving. That means not sweating my arse off, and looking at the speedo every second to make sure I'm not a single mile above the speed limit. I like having fun....I like flooring it from stops, I like redlining 1st and 2nd every now and then, I like getting closer towards triple digits while on an empty highway, I like taking corners and curves while going fast. And rather than stay behind semis, I do everything I reasonably can to get in front of them, I hate being around them.

 

[twoodcc]

I get low 20s city and high 20s highway, and have decided that getting more out isn't worth it. The cost is negligible, and I like being comfortable while driving. That means not sweating my arse off, and looking at the speedo every second to make sure I'm not a single mile above the speed limit. I like having fun....I like flooring it from stops, I like redlining 1st and 2nd every now and then, I like getting closer towards triple digits while on an empty highway, I like taking corners and curves while going fast. And rather than stay behind semis, I do everything I reasonably can to get in front of them, I hate being around them.

what do you drive?

i like to do some of those things also, but not all the time. especially with how gas has gone up. right now i'm doing this to save a little money, especially since i'm in college right now with no job. but the summer is almost here, and then i can work some and make a little money

 

[yg17]

what do you drive?

i like to do some of those things also, but not all the time. especially with how gas has gone up. right now i'm doing this to save a little money, especially since i'm in college right now with no job. but the summer is almost here, and then i can work some and make a little money

Hyundai Tiburon.

I've gotten more than 30mpg highway out of it, but I don't drive a lot, and the cost savings that I would get out of driving like grandma would be negligible. If I was filling up every day, things might be different, but I can go 2 to 3 weeks without filling up since I only have a 2 mile drive to work/school each day and the occasional grocery store run.

 

[Roger1]

Don't forget fender skirts.

I was thinking of Astroglide, myself. Just to make it slip through the air better.