What's the best way to accelerate to save gas?

[realazy]

So what is the best way to accelerate to use the least amount of gas?

I'm talking about slowing accelerating using less throttle input taking longer to get to the speed limit versus more throttle input but getting to the speed limit faster.

Assuming that after you get to the speed limit you will drive the exact same way.

[G-ZUS]

Slow and steady

[T-Dubbs]

more throttle= more gas

[Kloubek]

If you have a computer with real time fuel consumption, you will see that you use a ridiculous amount of gas flooring it. While I don't have links to any, there have been numerous studies saying that getting up to speed slowly is the best way to conserve gas.

With most vehicles, you can find that point that the engine doesn't strain and the transmission is in the most "comfortable" gear. Finding that sweet spot is probably your best bet for conservation.

[realazy]

The thing is with the real time consumption gauge in my car, if I slwoly accelerate at 10%-25% throttle, I feel like I'm bogging the car down and it shows approx. 25L-30L/100km.

If I do 50% throttle, I can get there much faster, but it maxes out the gauge at 39.5L/100km.

After I get to the speed limit and let off, I can usually get it to show about 10L-13L/100km.

[Eleanor]

Depends if you're going for fuel economy or thermodynamic efficiency :D

[schocker]

I generally accelerate faster as to not bog down the car and generally get quite good fuel economy :dunno:

[95teetee]

Getting to the speed limit in less than 5 seconds takes less time and therefore saves gas and ultimitely helps the planet.

Honest, Officer.

:D

[Xtrema]

Do not let the car stop and idle. So time yourself.

Also, the best mileage for most cars are around 100-120km/h. Make sure to do that on any street. :rofl:

[xnvy]

Originally posted by Xtrema
Also, the best mileage for most cars are around 100-120km/h. Make sure to do that on any street. :rofl: Sweet! I rarely go under that! :rofl:

[jwslam]

Originally posted by 95teetee
Getting to the speed limit in less than 5 seconds takes less time and therefore saves gas and ultimitely helps the planet.

Honest, Officer.

:D

This.
Accelerating slowly means I miss the green at the next intersection and I'm idling at a red, killing the environment.
If the light was gonna be red anyways... well I'm not using more/less gas by getting there sooner.

[G]

It's really pointless in my case...17.5L/100 or 18L/100 :banghead: After every fill I say I'll go easy on this tank but the torque is so addicting while gunning it out of the gas station lot.

[JZS_147]

you can install an injector pulse monitor and find the sweet spot for the car.

[Eleanor]

Originally posted by Xtrema
Also, the best mileage for most cars are around 100-120km/h. Actually it's closer to 90km/h typically, but there are a lot of other factors that play a part.

[Tik-Tok]

Originally posted by jwslam


This.
Accelerating slowly means I miss the green at the next intersection and I'm idling at a red, killing the environment.
If the light was gonna be red anyways... well I'm not using more/less gas by getting there sooner.

We should all start running reds to save the environment.

[JRSC00LUDE]

Originally posted by Eleanor
Actually it's closer to 90km/h typically, but there are a lot of other factors that play a part.

That's such an old wives tale of a generalization....

[Aleks]

Originally posted by JRSC00LUDE


That's such an old wives tale of a generalization....

You will burn less fuel going 90km/h than 120km/h in most cars :dunno:

[Kloubek]

Originally posted by Tik-Tok


We should all start running reds to save the environment.

I think a great way to help the environment would be to get rid of all the Multinova vans which sit there idling all freakin day.

[M.alex]

Don't be one of those assholes who accelerates to 100kph in 30seconds just to save a few cents. God I hate those people :banghead: :banghead: :banghead: :banghead:

[Hallowed_point]

Originally posted by G
It's really pointless in my case...17.5L/100 or 18L/100 :banghead: After every fill I say I'll go easy on this tank but the torque is so addicting while gunning it out of the gas station lot.

I have the exact same problem..:( but I look at it as smiles per gallon!! :burnout: My all time worst overall is 20.3 L/100 KM :facepalm:

[JRSC00LUDE]

Originally posted by Aleks


You will burn less fuel going 90km/h than 120km/h in most cars :dunno:

Your engines most efficient (forgive me, i'm not educated in physics) point is going to be at a particular load and rpm, that in itself has enough variables between cars (ie. power, torque, gearing, weight, etc.) to make a blanket statement of speed useless, no? Then you still have air resistance to factor into those variables that, as well, has its own set of considerations unique to each vehicle.

Not trying to start a debate, just don't agree with the statement based on what I said and just the overall experience of owning and driving a ton of different cars over the past 20 years. Could be wrong..... :dunno:

[BigBadVlad]

I recall reading that around 80 kph was typically Optimal and the secret to better gas mileage is don't brake. You're turning fuel energy into heat essentially.

[revelations]

The most effecient way to accelerate for my car (4 cylinder) is to shift into the next gear as soon as possible, without bogging the engine - around 2500rpmish.

Sometimes, on a decline, I intentionally skip a shit (eg 1-3, 3-5).



Also ::: why do people in Calgary tear away from a green light, just to go sit at a new red light ..... yet cant seem to find the accelerator pedal to merge on the highway at proper speeds :confused: :confused:

[schocker]

Originally posted by revelations

Also ::: why do people in Calgary tear away from a green light, just to go sit at a new red light ..... yet cant seem to find the accelerator pedal to merge on the highway at proper speeds :confused: :confused:
On the first part, my argument for people that say that is that you may say that when I am at the same red light as you, but the 90% of the time I do make it through before it is worth it :burnout:
I concur the second part though, merging onto stoney at 60km/h is an ideal speed.

[Mitsu3000gt]

If you drive normal and with the flow of traffic, any additional effort to save like $2 at the pumps is totally not worth it IMO.

I also think its best to accelerate as hard as possible to the desired speed because, say, 25L/100km for 3-4 seconds is better than 15 or so for like 20 seconds. Either way the difference at the pump is going to likely be far too small to worry about.

[ExtraSlow]

Originally posted by JRSC00LUDE
Your engines most efficient (forgive me, i'm not educated in physics) point is going to be at a particular load and rpm, that in itself has enough variables between cars (ie. power, torque, gearing, weight, etc.) to make a blanket statement of speed useless, no? Then you still have air resistance to factor into those variables that, as well, has its own set of considerations unique to each vehicle.
Yes, this is a complex problem, relating to engine, gearing, wind resistance, wieght etc.
However, one large factor, wind resistance, actually goes up with the square of the speed, which is why for most cars, the most efficient speed is under 100km/h.
Very aerodynamic cars have that point much higher. Like a corvett for instance. Tall gears and low drag mean it's very efficient at 120km/h and above.

[jonnycat]

No chance in hell either of my vehicles get 25L / 100kms while flooring it. I'd be surprised if they were under 50l/100kms.

[Eleanor]

Originally posted by JRSC00LUDE
That's such an old wives tale of a generalization.... Agreed, which is why I put a caveat on it.

Originally posted by JRSC00LUDE
Your engines most efficient (forgive me, i'm not educated in physics) point is going to be at a particular load and rpm, that in itself has enough variables between cars (ie. power, torque, gearing, weight, etc.) to make a blanket statement of speed useless, no? Then you still have air resistance to factor into those variables that, as well, has its own set of considerations unique to each vehicle. An engine is theoretically most thermodynamically efficient at peak torque, however that doesn't equate to fuel economy.

As you mentioned, there are a number of other factors that come into consideration for fuel economy.

[wardpr68]

If you want the greatest efficiency, pull the keys out of the ignition when you are going down a hill. :thumbsup:

[Toma]

As for the speed at best fuel economy.....

Remember, hp needed to overcome drag from tires and wind is SQUARED for both.

Since power is airflow, and we need a mass of fuel for every 14.7 masses of air, the less power we need, the better.

There will be a definite crossover somewhere between the 2 extremes of low speed, long time, and high speed, short time in terms of total fuel used.

Also, power needed to accelerate is also squared, but again, you have to balance that with very low accleration over an increased interval.

Better mileage tips are shit like get your tire pressure way up, and drive with a steady pedal. (fluctuating the pedal trips acceleration enrichment and on many cars can put you in open loop fuel control)

[Toma]

Originally posted by wardpr68
If you want the greatest efficiency, pull the keys out of the ignition when you are going down a hill. :thumbsup:

Not necessarily.... if you are above say ~2500 rpm, and let the engine slow you down, you are essentially in fuel cut anyway.

[wardpr68]

Originally posted by Toma


Not necessarily.... if you are above say ~2500 rpm, and let the engine slow you down, you are essentially in fuel cut anyway.

I disagree. You should try it.

[revelations]

Originally posted by wardpr68


I disagree. You should try it.

In my Civic, when I left off the gas when the car is in gear, the injectors cut out.....(my ScanGauge shows 0 LPH - litres per hour).

[ercchry]

Originally posted by revelations


In my Civic, when I left off the gas when the car is in gear, the injectors cut out.....(my ScanGauge shows 0 LPH - litres per hour).

he is just trying to make people crash (loss of brakes/steering), ignore him...

[supe]

I think there are two topics that come into play. One is most fuel efficient speed vs most efficient acceleration style.

Most fuel efficient speed in my v6 sedan is around 90-100km/hr with low RPM.

Most fuel efficient acceleration is another topic of controversy. I think the most fuel efficient acceleration is closer to where you get maximum hp, which pushes out the torque over the least amount of time.

In my car which as a fuel usage sensor, it doesn't matter how fast or how slow I'm accelerating, just the act of accelerating pushes the meter to the max, so perhaps the best way to minimize fuel usage is to accelerate over the quickest amount of time.

Of course overall fuel efficiency does not mean accelerating hard every time because you have to factor in distance and other variables. Bagging on the throttle to hit a red light the next block is pretty much the worst thing you can do.

These are just opinions I would love for someone to critique logically.

[Mista Bob]

:facepalm:

I really hope no one seriously thinks they are going to save fuel by accelerating faster.
There is a reason why hypermilers accelerate as slowly as humanly possible.

They don't get far above their cars mpg rating by gaining speed fast.
Also using the in-dash fuel consumption meter for real time readings is horribly, horribly inaccurate.

And short of a car having very messed up gearing, you will pretty much always use less fuel at 90kph vs 110...even more so vs 120.
There are so many factors that affect fuel mileage negatively and they only get worse the faster you go.

Has anyone here even tried testing these things out in their car long term??

[DboyNismo]

Originally posted by revelations
Sometimes, on a decline, I intentionally skip a shit (eg 1-3, 3-5).

I've never tried skipping shits before. Must be interesting... what about uphill? Do you take double shits?

:rofl:

LOL dw I know what you mean. Just messing around.

[Twin_Cam_Turbo]

I accelerate at 1/2 to 3/4 throttle and shift at 3000-3500rpm for maximum fun and minimal fuel economy loss.

[95teetee]

Originally posted by Mista Bob
:facepalm:

I really hope no one seriously thinks they are going to save fuel by accelerating faster.
I really hope no one seriously thinks we mean it when we say we think we're saving gas by accelerating faster.

What we're really saying is that it's a lot more fun, and we don't really care that it hurts our gas mileage a little.

[ercchry]

i like to vary my speed so i can continually listen to my exhaust pop and gurgle, it gives me the most enjoyment.

[g-m]

I figure the amount of gas I burn is directly proportional to the amount of fun I had while driving. If my mileage is good its pretty much a direct indicator of a shitty week

[FiveFreshFish]

If I combine just one trip with another per tank of gas, I will have saved more fuel than I can ever achieve with hyper-miler techniques.

[msommers]

http://2.bp.blogspot.com/_lQSC5XxIn9A/SQweJaKK3JI/AAAAAAAAAJk/uLUeuOS4jMw/s400/hypermiler.jpg

[DboyNismo]

Although hyper-miling sounds good in theory, it is pretty stupid and dangerous. like ^ the people who drive slow just to "save gas" when they get into an accident and their insurance goes up...where did all those $$ saved from gas go?

[89s1]

From a thread almost a year ago exactly....


Originally posted by 89s1
If it takes you over 3 blocks to accelerate from 0-60 km/h you should just take the bus.

:rolleyes:

[DboyNismo]

^ says the guy with the honda? :rofl: :rofl: LOL just kidding.

[rage2]

Posted this a while ago on another forum. Hypermiling works, and accelerating as slow as humanly possible and keeping revs as low as possible uses the least amount of fuel.

I had a conversation with someone over dinner about hypermiling, so for fun I decided to hypermile my C63 across the city. Didn't touch the brakes once, pissed off a lot of people rolling up to the lights, tailgated every truck or van I could, took perfect lines and hit every apex of every corner, and managed 9.9L/100km (23.8mpg) lol.

http://i1213.photobucket.com/albums/cc475/rage2amg/ef84bd2b.jpg

Was quite the shitty drive though so I'm never doing it again. I usually average 11mpg in the summers, and averaging 14.8mpg over the life of the vehicle (40,000kms).

[Freeskier]

Originally posted by Eleanor
Depends if you're going for fuel economy or thermodynamic efficiency :D

I knew that was you before I even read your username.

[Hallowed_point]

Originally posted by ercchry
i like to vary my speed so i can continually listen to my exhaust pop and gurgle, it gives me the most enjoyment.

:werd: same here

[supe]

In response to the hyper milers statement I found this on another site:


To the best of my understanding SAE Supermilers (an SAE competition) run their engines at near full-power while they are accelerating to a certain speed, then shut off the engine and coast down to nearly 0mph before starting their engine again and accelerating back up. It's a great way to get high fuel economy, winners get over 2,000mpg, but not very practicable on public highways.

Again not practicable, but in theory its best to accelerate quick. Still researching the web...

[supe]

Here is another source that says accelerating slowly actually doesn't work (with a fancy graph)

http://autos.yahoo.com/news/6-driving-tactics-to-save-gas-this-summer.html?page=1



Conventional wisdom says that jackrabbit starts consume more fuel. But it turns out that nursing your speed up to the limit too slowly also lowers mpg. How can that be? Cars get poorer fuel economy in lower gears, and accelerating too slowly prevents up-shifting at an efficient rate. The best acceleration rate varies with the vehicle, gear ratios and weight. But in our testing we found that taking 15 seconds to accelerate to 50 mph used less fuel than taking 30 seconds to reach the same speed, because the car entered its top, fuel-​saving gear sooner.

[realazy]

^ That's exactly what I was looking for.

[gogreen]

Originally posted by supe
In response to the hyper milers statement I found this on another site:



Again not practicable, but in theory its best to accelerate quick. Still researching the web...

I was just thinking of posting about that. It's known as pulse-glide, but as I understand it you don't coast all the way down to a near-stop. The idea is if your target speed is 100 km/h, you would accelerate at WOT to 120 km/h, kill the igniton (without moving the key to the "Lock" position, obviously), coast in neutral down to about 80 km/h, restart the engine (cars with standard transmissions can be "bump-started" with the clutch), accelerate back up to 120 km/h and repeat.

Still impractical in my opinion, but the key point being that not all hypermilers accelerate slowly.

That's not to say that accelerating at WOT and then maintaining a target speed would be equivalent.

[JRSC00LUDE]

Originally posted by gogreen
I was just thinking of posting about that. It's known as pulse-glide, but as I understand it you don't coast all the way down to a near-stop. The idea is if your target speed is 100 km/h, you would accelerate at WOT to 120 km/h, kill the igniton (without moving the key to the "Lock" position, obviously), coast in neutral down to about 80 km/h, restart the engine (cars with standard transmissions can be "bump-started" with the clutch), accelerate back up to 120 km/h and repeat.

Still impractical in my opinion, but the key point being that not all hypermilers accelerate slowly.


That could only possibly be entertaining if you were high.....but then you likely shouldn't be driving. Wow, what a pain in the ass method of saving a couple bucks. I don't think i'd even want to be friends with someone who's so cheap they live their life like that.

[msommers]

Starting your engine so many additional times would probably end up costing you more in maintenance than saving money on gas.

[Xtrema]

Originally posted by msommers
Starting your engine so many additional times would probably end up costing you more in maintenance than saving money on gas.

BMW, Kia and Hyundai all have start/stop tech. So you probably don't have a choice unless you keep turning off the eco button.

Who care about longevity as long as it pass CAFE. Manufacturers doesn't want your car to last more than 5-6 years anyway.

[jwslam]

Originally posted by gogreen
(cars with standard transmissions can be "bump-started" with the clutch)

I've always wondered... how does that work with cars nowadays with the stupid clutch-to-start feature?

[Sugarphreak]

...

[J-hop]

Not sure if this has been mentioned but I think fuel economy has a lot to do with peak torque and volumetric efficiency.

One way that can be used as a gauge for VE is vacuum (for an NA motor). Vacuum is more or less directly correlated to volumetric efficiency. You'll notice when you dump the throttle your vacuum gauge should decrease quit rapidly showing a decrease in the volumetric efficiency of your engine. So essentially you can say per liter of fuel you get less HP.

Staying near the peak of your torque curve and in the best VE zone you can maximize your fuel economy. This is so different from car to car though, an s2000 for example will require different driving habits than a corvette to maximize fuel economy, there really are no blanket instructions that can be given.

[PartyintheKorea]

fuel economy is about a lot more than acceleration, although it is very important.
the point is to not press the brake or mash the accelerator as much as possible.
when you brake, the momentum you built up is converted into heat energy, and it's gone forever.
coast down hills in neutral, not as ridiculous as shutting the engine off.
don't go down hills in gear unless you need to accelerate quickly, it creates unwanted drag.
avoid stretches that combine high speed and inclines. the last thing you want is to drive up a steep hill with your foot hard on the throttle in 4th gear.
shut your engine off at a stop light only if you're gonna be absolutely certain that you'll be sitting at least 10 seconds or so.
tune your car for low-end torque. peak hp/tq means nothing in the city, so keep your cat.

there's also a technique called pulse & glide. basically if you want an avg speed of say 70 kph, you accelerate smoothly up to 80 kph then coast down to 60 kph and repeat the process. you use negligible gas while coasting, and if you accelerate correctly, your coasting mileage will drastically offset your accelerating mileage, giving you better COMBINED mileage compared to cruising.

[alloroc]

Originally posted by Mista Bob
:facepalm:

Has anyone here even tried testing these things out in their car long term??

Yes Tested.

In a standard anyway ...

Easy on throttle in 1'st to 2500 rpm then WOT short shift is most efficient.

Edit ..

I keep up with traffic and do a full rpm accelleration to 100k at least once a day yet I still get less than 9L / 100k in the city. In a 3500 Lb AWD car.