Top Ten Fuel Saving Tips

[monty73741]

1 Avoid High Speeds As your speed increases, your aerodynamic drag increases in an exponential fashion. Driving 62 mph (100 km/h) vs 75 mph (120 km/h) will reduce fuel consumption by about 15%.
2 Do Not Accelerate or Brake Hard By anticipating the traffic and applying slow steady acceleration and braking, fuel economy may increase by as much as 20%.
3 Keep Tires Properly Inflated Keep tire air pressure at the level recommended by your vehicle manufacturer. A single tire under inflated by 2 PSI, increases fuel consumption by 1%.
4 Use A/C Sparingly When the air conditioner is on it puts extra load on the engine forcing more fuel to be used (by about 20%). The defrost position on most vehicles also uses the air conditioner.
5 Keep Windows Closed Windows open, especially at highway speeds, increase drag and result in decreased fuel economy of up to 10%.
6 Service Vehicle Regularly Proper maintenance avoids poor fuel economy related to dirty air filters, old spark plugs or low fluid levels.
7 Use Cruise Control Maintaining a constant speed over long distances often saves gas.
8 Avoid Heavy Loads Remove the sand bags from your trunk in the spring and pack lightly for long trips.
9 Avoid Long Idles If you anticipate being stopped for more than 1 minute, shut off the car. Restarting the car uses less fuel than letting it idle for this time.
10 Purchase a Fuel Efficient Vehicle When buying a new vehicle examine the vehicle's rated fuel efficiency. Usually choosing a small vehicle with a manual transmission will provide you with great fuel economy

[Famine]

Just to add, #5 is more important than #4. Open windows will obliterate your fuel economy much more than having your aircon on, due to #1.

(and #1 isn't totally true. As your speed increases, your aerodynamic drag increases by the factor of a square of the speed increase, and power required increases by the factor of a cube)

I will add on:
#11 Keep your windows clean. If your windows are dirty they are more likely to mist up in cold weather, meaning you'll have to put the blowers on to clear it. The more electrical load on your car, the more fuel is used.
#12 Keep your car IN GEAR whilst decelerating. A modern EFi engine will use enough fuel to keep it at idle if you disengage the clutch, but whilst the clutch is engaged and you are decelerating the wheels drive the engine and the injectors shut off. The engine will use no fuel at all.
#13 Keep as little in the car as you need. Weight kills fuel economy. Someone once showed that having a moustache costs you £2 a year (for an average mileage car) in petrol to carry around, through the additional weight.

[atlantamx3]

#12 Keep your car IN GEAR whilst decelerating. A modern EFi engine will use enough fuel to keep it at idle if you disengage the clutch, but whilst the clutch is engaged and you are decelerating the wheels drive the engine and the injectors shut off. The engine will use no fuel at all.

I dont see this as being possible. The motor is still turning over. Fuel has to be pumped into the Cylinders for combustion to happen. Without Fuel, the cylinders would just be detonating and blowing up your cylinder head.

[Nd4SpdSe]

9 Avoid Long Idles If you anticipate being stopped for more than 1 minute, shut off the car. Restarting the car uses less fuel than letting it idle for this time.

To this, remember that "90% of your engine wear happens at startup"

The current trend is the "90% of your engine wear happens at startup" advertising ploy. This fact is absolutely true, but as it happens, it's less to to with "grinding engine parts" and more to do with combustion. When the combustion gases burn, they form acids which are highly corrosive when their vapours condense. These acids collect in the upper cylinder areas where their temperature is raised above their dew point. The acids condense and etch the cylinder walls and piston rings. In reality, this accounts for over 85% of engine wear, the other 15% being down to abrasion. So the adverts are nearly right - most of the engine wear does happen at startup, and it is because of a lack of oil, but it isn't because the oil isn't coating moving parts - it's because it's not transporting these acidic gases away. Having said that, if you start the engine and let it idle for 15 seconds or so before moving off, you can probably add another 100,000 miles to your engine's life without one bottle of additive. This warms the oil up a tad and makes sure it's in all the most vital areas before you start putting a strain on the engine. Most handbooks tell you not to let the engine warm up before driving off (they're referring to the acid corrosion mentioned above), but they mean don't let it reach working temperature. If, however, you insist on starting up and belting off down the road, think of this next time: it takes an average engine around 3 minutes of average driving for the exhaust manifold to reach 300°C. If you blast off and run around at full throttle, right from the word go, that process takes a little under a minute. Think about it - from outside air temperature to 300°C in a minute - what exactly is that doing to the metal in your manifold? Ask anyone who's ever owned an original Audi Quattro - they'll tell you exactly what happens.

http://www.chris-longhurst.com/carbibles/additives.html

[Tunes67]

Just to add, #5 is more important than #4. Open windows will obliterate your fuel economy much more than having your aircon on, due to #1.

(and #1 isn't totally true. As your speed increases, your aerodynamic drag increases by the factor of a square of the speed increase, and power required increases by the factor of a cube)

Actually.. this is a myth that was busted on the Discovery Channels Mythbusters show. They took 2 identical ford exploders and ran them at a track each with exactly 5 gallons of fuel.. one with the windows up and A/C on and one with the A/C off with the windows down.. The Exploder that ran without A/C and with windows down ran an extra 25 laps around the track beyond what the A/C Exploder did off the same exact amount of fuel. Considering that Ford Exploders have the aerodynamics of a freaking brick.. you can figure that A/C does indeed reduce your gas mileage far more than having your windows down.

Tunes67

[Famine]

Just to add, #5 is more important than #4. Open windows will obliterate your fuel economy much more than having your aircon on, due to #1.

(and #1 isn't totally true. As your speed increases, your aerodynamic drag increases by the factor of a square of the speed increase, and power required increases by the factor of a cube)

Actually.. this is a myth that was busted on the Discovery Channels Mythbusters show. They took 2 identical ford exploders and ran them at a track each with exactly 5 gallons of fuel.. one with the windows up and A/C on and one with the A/C off with the windows down.. The Exploder that ran without A/C and with windows down ran an extra 25 laps around the track beyond what the A/C Exploder did off the same exact amount of fuel. Considering that Ford Exploders have the aerodynamics of a freaking brick.. you can figure that A/C does indeed reduce your gas mileage far more than having your windows down.

Tunes67

Since the Explorer already has ropey aerodynamics, opening the windows wouldn't harm them signficantly, whereas the same increase in drag coefficient for a more slippery car - like, say, the MX-3 - would have more drastic effects.

I believe this was demonstrated on the British TV show "Fifth Gear", though I cannot remember what car they used.

Still, I think we can safely say that both are bad

I dont see this as being possible. The motor is still turning over. Fuel has to be pumped into the Cylinders for combustion to happen. Without Fuel, the cylinders would just be detonating and blowing up your cylinder head.

Without fuel, how would anything in the cylinders detonate at all?

Look it up if you don't believe me. Under deceleration in gear the wheels drive the crank (rather than the other way round). A modern EFi will, at this point, stop putting fuel into the cylinders and no fuel is used. Dip the clutch and suddenly the engine needs enough fuel to idle, putting in as much fuel as is necessary.

Coasting to that stoplight hurts your fuel economy. Keep it in gear - and the V6 MX-3 will happily go down to 10mph in 5th - and you'll save fuel (and money). I promise.

[neutral]

I will add on:
#11 Keep your windows clean. If your windows are dirty they are more likely to mist up in cold weather, meaning you'll have to put the blowers on to clear it. The more electrical load on your car, the more fuel is used.
#12 Keep your car IN GEAR whilst decelerating. A modern EFi engine will use enough fuel to keep it at idle if you disengage the clutch, but whilst the clutch is engaged and you are decelerating the wheels drive the engine and the injectors shut off. The engine will use no fuel at all.
#13 Keep as little in the car as you need. Weight kills fuel economy. Someone once showed that having a moustache costs you £2 a year (for an average mileage car) in petrol to carry around, through the additional weight.

#14 Drive Less. Extensive studies have shown that driving 15% less will save 15% in fuel costs, driving 20% less = 20% savings etc. It's damn magic yup.

[Famine]

I will add on:
#11 Keep your windows clean. If your windows are dirty they are more likely to mist up in cold weather, meaning you'll have to put the blowers on to clear it. The more electrical load on your car, the more fuel is used.
#12 Keep your car IN GEAR whilst decelerating. A modern EFi engine will use enough fuel to keep it at idle if you disengage the clutch, but whilst the clutch is engaged and you are decelerating the wheels drive the engine and the injectors shut off. The engine will use no fuel at all.
#13 Keep as little in the car as you need. Weight kills fuel economy. Someone once showed that having a moustache costs you £2 a year (for an average mileage car) in petrol to carry around, through the additional weight.

#14 Drive Less. Extensive studies have shown that driving 15% less will save 15% in fuel costs, driving 20% less = 20% savings etc. It's damn magic yup.

Bwaaaaaaaaaaaaaaaaaaahahaha!

How did you come across this information? It's akin to witchcraft!

[Tunes67]

Since the Explorer already has ropey aerodynamics, opening the windows wouldn't harm them signficantly, whereas the same increase in drag coefficient for a more slippery car - like, say, the MX-3 - would have more drastic effects

I think this is going to be something that can only be determined by a case by case situation. If you roll down the windows of a brick.. its going to have even more drag making it even less fuel efficient. As for significantly increasing the drag of a car that is supposed to be more aerodynamic.. I think it would depend on the car. For example.. I have a 1985 Subaru XT that has an extremely low drag coefficient.. .28 according to the production specifications. Now this car is a beater.. there is body damage and we can assume that its probably not as efficient aerodynamically as it was from the factory. So for arguments sake.. we will say it has a drag coefficient equivalent to a MX-3 RS version.. which according to MX-3.com's listing of specifications is at .32. When I drive the Subaru in the rain on the freeway.. I can have the drivers door window down almost 1/4 of the way and the wind keeps the rain out of the cabin. In my MX-3.. even cracked only a 1/2 inch.. rain still gets into the cabin even at freeway speeds. Assuming that the cars have similar drag coefficients.. the only thing that could cause this would be the design charateristics of the two cars. And with the Subaru as an example.. I can tell you from personal experience.. that the car gets almost 40mpg on the freeway with the windows up, A/C OFF. And gets only 36 mpg with the windows down and the A/C off. With the A/C on & windows up.. the car only averages 34 MPG. Mind you I do have the timing advanced beyond factory specifications and I do run only premium gas in my cars. And this was with 5W-30W oil in the engine (this is of note because the car gets worse mileage with heavier oils like 10-30 or straight 30W. But it does burn a bit more oil with the 5-30 in it.) Since I dont have A/C in my MX-3.. I cant test it for the same thing.. however I can assume since the drag coefficients are similar that the effect would be similar as well. Cheers

Tunes67

[Famine]

Since the Explorer already has ropey aerodynamics, opening the windows wouldn't harm them signficantly, whereas the same increase in drag coefficient for a more slippery car - like, say, the MX-3 - would have more drastic effects

I think this is going to be something that can only be determined by a case by case situation. If you roll down the windows of a brick.. its going to have even more drag making it even less fuel efficient. As for significantly increasing the drag of a car that is supposed to be more aerodynamic.. I think it would depend on the car. For example.. I have a 1985 Subaru XT that has an extremely low drag coefficient.. .28 according to the production specifications. Now this car is a beater.. there is body damage and we can assume that its probably not as efficient aerodynamically as it was from the factory. So for arguments sake.. we will say it has a drag coefficient equivalent to a MX-3 RS version.. which according to MX-3.com's listing of specifications is at .32. When I drive the Subaru in the rain on the freeway.. I can have the drivers door window down almost 1/4 of the way and the wind keeps the rain out of the cabin. In my MX-3.. even cracked only a 1/2 inch.. rain still gets into the cabin even at freeway speeds. Assuming that the cars have similar drag coefficients.. the only thing that could cause this would be the design charateristics of the two cars. And with the Subaru as an example.. I can tell you from personal experience.. that the car gets almost 40mpg on the freeway with the windows up, A/C OFF. And gets only 36 mpg with the windows down and the A/C off. With the A/C on & windows up.. the car only averages 34 MPG. Mind you I do have the timing advanced beyond factory specifications and I do run only premium gas in my cars. And this was with 5W-30W oil in the engine (this is of note because the car gets worse mileage with heavier oils like 10-30 or straight 30W. But it does burn a bit more oil with the 5-30 in it.) Since I dont have A/C in my MX-3.. I cant test it for the same thing.. however I can assume since the drag coefficients are similar that the effect would be similar as well. Cheers

Tunes67

Agreed.

Though I DO have aircon on mine and on a long blat at motorway speeds (errrr... "70"mph) airconditioning scarcely affects the fuel economy - we're talking single digit percentages - but open windows kills it dead.

This is scarcely scientific, single-variable testing though.

[hgallegos915]

yup I also saw that sho on mythbusters it was interesting.

Just to add, #5 is more important than #4. Open windows will obliterate your fuel economy much more than having your aircon on, due to #1.

(and #1 isn't totally true. As your speed increases, your aerodynamic drag increases by the factor of a square of the speed increase, and power required increases by the factor of a cube)

Actually.. this is a myth that was busted on the Discovery Channels Mythbusters show. They took 2 identical ford exploders and ran them at a track each with exactly 5 gallons of fuel.. one with the windows up and A/C on and one with the A/C off with the windows down.. The Exploder that ran without A/C and with windows down ran an extra 25 laps around the track beyond what the A/C Exploder did off the same exact amount of fuel. Considering that Ford Exploders have the aerodynamics of a freaking brick.. you can figure that A/C does indeed reduce your gas mileage far more than having your windows down.

Tunes67

[snellgrove]

get rid of number 10 lol, we all didn't do that one

as for the comments about 90% of engine damage happens at startup, and avoiding long idles..

if you turn a hot engine off, and after say 2 minutes on again.. its not going to do much damage at all, as the oil is still really hot and protective, -and also runny! the oil pump can quickly squirt it all back around the system again unlike viscious, cold oil.

never, ever idle a car to warmth!! no oil pressure due to low revs, and cold hard-to-pump oil... not a good combination!

turn the key, and go drive it.. dont sit on the drive

(dont rev it hard tho when its cold... again, cold oil.. not good idea)

[D323]

I agree, #1 is wrong. You get the best mpg avg @ 70mph. Do the math, 2 identical cars, both have 10 gallons, one does 35 mph constant, the other 70 mph. The car that does 70 will go the furthest. The MPG is a parabola when graphed, and peaks @ 70, where most car manufacturers setup the car to ride at.

[Gro Harlem]

The aircon thing has to do with the engine's output as well.

I know on my MX3 the a/c has NO EFFECT WHATSOEVER on the fuel consumption. Sounds like a load of BS but its true. I document every tank of gas I fill up in a lil notebook and when comparing my winter-time (don't have a/c on) fill ups with summer time (have it on 100% of the time) there is no difference.

I think it has to do with the fact the klze has so much additional power that isn't being used that the a/c clutch engaging is negligable when it kicks on.


On my 96' Slowtege, the a/c destroys the fuel econ by almost 10mpg's! Probably b/c the car has a shitty 1.5 liter which can barely keep up with traffic as it is.

[neutral]

The aircon thing has to do with the engine's output as well.

I know on my MX3 the a/c has NO EFFECT WHATSOEVER on the fuel consumption. Sounds like a load of BS but its true. I document every tank of gas I fill up in a lil notebook and when comparing my winter-time (don't have a/c on) fill ups with summer time (have it on 100% of the time) there is no difference.

I think it has to do with the fact the klze has so much additional power that isn't being used that the a/c clutch engaging is negligable when it kicks on.

That could be the case. I had a Dodge Ram250 Van w/5.9L 4bbl Holley V8. That motor seemed to generate mileage that was virtually the same whether a/c was on or not. Even loading a couple thousand+ lbs. of ppl & cargo hardly nudged the mileage. I finally fig'd it was for the same kinda reasons - that setup was such a high output & heavy duty torqued muther that it just laughed & shrugged it off when the a/c was on.

p.s. So we're talkin 10.5 -11 mpg for that beast - and with a 35 gallon gas tank. At today's gas $, glad to have sold it 4 yrs. ago when I got the MX-3.