aunggu2002

Let's admit it, gas is only going to get pricier. And the people on these forums aren't exactly to types to get a Toyota Prius anytime soon. So let's talk about doing what we can do our cars to get better economy and still be able to keep our cool cars.

What are the best ways to improve fuel economy? The way I see it, we can either lower our car's overall weight which'll improve economy and performance, or we can focus specifically on fuel economy and driving habits.

Lowering Weight:

-Get lighter hoods replacement - like carbon fiber
-Get lighter rims
-Take all the boxes and crap out of our trunks

Fuel Economy

-Don't over rev above 3000 rpm
-Chips? -- will the chips really work for economy?
-Tornado/ Throttle Body air tornado -- will that device do anything for MPG?

Any other ideas welcome.

DFoster0

tire pressure, slower driving on the highway

artec

hey the other week i changed my spark plugs ( prior to doing so, i kept track of how many km's i got ( 3 fillups ) and since changing ( past 3 fillups ) i have noticed a decrease in consumption and 75more kms on avg!!. so make sure your spark plugs are in good working order. also keep your goddamn air filter clean. those are the two mechanical ways to improve fuel consumption.

studebaker

Potential aids are .....possibly Icebox air intake or other, Using Mobil-1 or other synthetic oils.
Driving techniques can really be a big factor..... some examples on sites devoted to mileage.
Imitating trucks.... they try never to come to a complete stop - anticipate and time stoplights.
Getting 91 by mixing 93 and 89 octane. Headers? Tires with less rolling resistance?

Every thing adds a bit more - combining is effective.
Luckily our engine is quite efficient if given a chance.

2K1CLtypeS

Basic gas saving things you can do:

-Keep your tires properly inflated (32-35psi)
-Have your alignment checked if your tires are wearing uneven
-Avoid fast accelaration and drive at moderate speeds
-Keep your engine tuned
-Remove all objects from your trunk that can add weight to your car.
-When driving on the freeways, keep your windows closed and ac on. The drag on your car when your windows are open(wind drag)burns more fuel than with the windows rolled up and ac running (if you don't need to run your ac, that's even better yet!)
-Use synthetic engine oils

I don't think adding cf hoods or trunk lids will will be cost effective. For the $$$ you pay for the cf hood or trunk lids, how long will it take to recoupe the cost you invested in them vs fuel savings? In my experience adding headers, intake and UR pulley really help improve my gas mileage as well as increase in hp. Stay away from those gagets like the Tornado. They don't help fuel economy.

aznboi2424

iTrader: (10)

driving can yield you almost 40mpg all highway. check out www.drive55.org
I want one of those bumper stickers, so people wont look at me funny on the freeway lol

miker_types

well i dont know if this is true or not, but i've started driving in SS mode almost exclusively, and upshift early all the time, im in 5 at 35, helps keep my RPMS crazy low, and i've noticed a fuel improvement

Accord_V6_400m

iTrader: (1)

changine out the O2 sensor, avoid universals if you can, I got one and it hesitates from time to time, damn wiring crap.

fuzzy02CLS

iTrader: (2)

Drive slower.

GreenMonster

Jack rabbit starts and quick stops eat into the mileage...

Take off slow and coast up to stop signs/lights...

.... or buy a civic

Sideswipe

I only have 89K on my CL-S but I think I'll change my spark plugs. One thing I've also done is to shift into nuetral when I'm coming to a redlight instead of staying in drive. When you think about how much more pressure you have to apply to your breaks to overcome the auto tranny downshifting you'd be surprised how much easier it is to stop while in neutral. You'll not only save a few drops of gas your breaks will also last longer.

Sideswipe

Anybody know the lifespan of an O2 sensor on a CL-S?

TheWeez

Air intake or K&N, header, pulleys, and a light foot.

aunggu2002

Can anyone confirm this? I'm not sure that having the AC on makes up for the drag of having the windows up. The AC kills gas quiet fast. Anyone actually tested this and have seen a noticible result like this poster is saying?? Because if it's true, I wouldn't mind doing that. AC kicks a lot more ass than having the windows down on freeway, but I always thought it was the other way around so I had the windows down most of the times.

One of my friends added headers and he actually lost MPG. For most of you guys, did the headers add MPG or make you lose them? Assuming you don't wang it all the time.

aunggu2002

I don't believe that driver slower necessarily saves gas - especially truer on freeways. Last time I went long distance, I went 470 miles on one tank. That's close to 35 mpg on freeway.

I went 70-80 the whole way under automatic mode, didn't let the rpm touch 3000x.

Since our cars are v6's and have plenty of pushing power, even at 80mph, we're only crusing at 2000 rpm in the 5th gear so our gas does great.

And since u get to where you're going faster at 80, it makes up for cost of gas by driving slower which would consume gas at a longer rate because the travel time is longer.

zac

5th at 35mph! Didnt know that was even possible.
Its not always good to have the higher gear and lower speed, but almost always. For example, going up a hill use a lower gear, and get some speed before it.

zac

Loss of MPG with windows down is insignificant. With air-conditioning its around 1MPG. According to these guys.

http://www.consumerreports.org/cro/c...-406/index.htm

Corrosion

1 MPG my ass. When I have my A/C on I swear I can see that needle moving.

fsttyms1

Sell the car and buy a Geo Metro

miker_types

ouch....

dannypio

Whats the best time to change plugs for best mileage? I have 62k miles on my 2002.

TheWeez

The headers will actually improve gas mileage as you are making more power throughout the RPM range meaning that you need slightly less to make the same speed. What happens most times is that the addition of more power makes people drive the car harder. You don't supercharge your Viper to drive 55.

TheWeez

No real specific time to change them. Do them now if they haven't been done and see what happens. They're cheap.

LIPPSTUH

iTrader: (2)

no point of buying parts just to save on gas.... drive slower its not rocket science.... =D

my best gas saver is having my gf drive me in her car =D

Accord_V6_400m

iTrader: (1)

Save air conditioning for higher speeds, like 80+

Opening windows is so vague, do they mean all the way for all four windows or just one window?

As for the O2 sensor I changed mine out at 84K seemed to go from 20 to 22mpg.
It seems that the planar type O2 sensor does a better job of not fouling up versus the thimble type that can get dirtier.

CLTypeSixspeed

driving stick i try to keep the revs low, sometimes do the neutral thing but i read in some car magazine, i forget if it was motortrend or car and driver,that the gas your using to keep the engine running in neutral is more than being off the gas in gear

Accord_V6_400m

iTrader: (1)

In gear and off gas means your using no gas until it gets to about 1000rpms and starts to stall on you. neutral and no gas is obviously you idling anything below ~1K is using gas.

Usually its better to stay in gear because it helps brake the car, its actually illegal in most places to cruise in neutral, yeah I know its weird and hard to define.

aunggu2002

I don't take the whole "drive slower" thing as a good advice. I mean, the opportunity cost of driver slower for long distances offsets any fuel economy gains to begin with - so really, you just end up arriving at the place slower. Let's assume you make $7 an hour. If you drive at 55mph, you will have traveled 55miles in one hour. If you drive 80 miles per hour, you will have driven 80 miles in one hour. So the difference between the two is 25 miles more traveled. If you can get to where you're going faster or 25 miles further in the same hour, the cost of fuel is offset with your assumed hourly wage!!

Since our cars are v6, cruising at 80 mph only puts us at around 2000x rpm on the tech. Our engines don't burn too much fuel as long as we keep the rpm under 3000x so our cars work great freeway, but it's the city that kills us.

And the driving slower advice doesn't matter in the city because it's safe to assume most of us aren't stupid to drive fast in cities anyways.

I would look into the AC/ window down drag. From what I understand and from personal experience, AC kills gas SOOOO fast it's not even funny. Having the windows down seem like a hell of a lot better way to go.

GreenMonster

Ah.... I don't even know where to begin...

There's a reason why there's speed limits now... Not only for safety, but there's countless studies that have proven that driving slower increases fuel economy. Most cars make the optimum economy figures at around 55-65 mph.

If you have to show up to work until 8:00, it doesn't matter if you get there any sooner than 8:00. You could drive at the speed of light, and they ain't gonna pay you for showing up an hour sooner than you're scheduled... Work doesn't care how long it takes you to get to work, as long as you show up on time.

You're "more miles traveled" logic is bullshit too... If you work 25 miles from home, you're going to drive 25 miles. Doesn't matter how fast you go, it's still 25 miles. There just ain't no "more miles traveled". The time saved is insignificant. Do the math (assuming 25 miles to work):

80mph => 25 miles * 60 minutes/80 mph = 18.75 minutes

65mph => 25 miles * 60 minutes/65 mph = 23.08 minutes

So you can save 4.33 minutes each way (which you ain't gonna get paid for) by driving 80, or you can save up to 35 percent on gas by driving slower:

http://money.cnn.com/2006/05/01/Auto..._mpg/index.htm (google "drive slower saves gas" without the quotes for more info).

I drive 80 mph (when traffic allows) to and from work, but I get better gas mileage when I set the cruise control on 65. I didn't realize how little time I saved until I passed a co-worker (who drives 65) on the way to work while going 80. She pulled in a couple minutes after I did (23 mile commute).

Check out http://www.gassavers.org/index.php for more tips on saving gas...

Summary: If you are serious about saving gas, just slow down, or take the bus to work...

GreenMonster

From Mythbusters:

http://kwc.org/mythbusters/2004/11/m..._catapult.html

aunggu2002

80mph versus 65mph yields a difference of 25 miles per hour traveled.

The question is - how much extra gas is burned in an hour traveling at 80 versus 65.Our cars get better than 25 miles per gallon but let's assume it's only 25 freeway. So hypothetically - that's an extra gallon burned going 80 versus 65. So that's an extra $4 that is burned up going 80 versus 65 every hour traveled.

That also means within one hour, at 80mph speed, you travel 25 miles further.

If you drove slower at 65mph, you would've had to travel longer. That means you'd have to travel another 23.08 minutes for the extra 25 miles further.

So although you burned extra $4 worth of fuel going 80mph, it's offset by the fact that you'll go another 25 miles traveling longer, using up more time and more fuel at 65mph.

So back to what I was saying: it's the same damn thing in the end. So if I'm going to use up same fuel traveling, I might as well get there faster.

Also - at both 65 and 80 mph, our v6 engines are not revving above 3000 rpm at any time. This means we're pretty damn efficient and the engine is pretty idled compared to other v4's that are at 4000 rpm around 75 - 80mph.

CL6

how much are you willing to change your driving to save $5 or $10?

TheWeez

That's still wrong. You're assuming that you get the same gas mileage traveling at 80 that you would at 65. That's untrue. As others have said, gas mileage drops off quickly after about 65mph. You're not going to win this one.

TheWeez

As speed inceases you have higher air resistance and thus it requires more fuel to achieve that speed.

"Driving at 45 rather than 65 mph (72 rather than 105 km/h), results in about one-third the power to overcome wind resistance, or about one half the energy per unit distance, and much greater fuel economy can be achieved. Increasing speed to 90 mph from 65 mph increases the power requirement by 2.6 times, the energy by 1.9 times, and drastically decreases fuel economy. In practice, rather than doubling or halving the fuel economy, the difference is actually closer to 40-50%, because engine efficiency varies greatly with the torque/speed operating point."

Parliamentary Advisory Council for Transport Safety
"Vehicles travelling at 80mph use 10 to 20 per cent more fuel than traveling at 70mph."

My previous car's owner's manual said driving 65mph versus 55mph uses 15% more gas.

Plenty more info here:
http://en.wikipedia.org/wiki/Fuel_ec...in_automobiles

Moodist

iTrader: (2)

I switched my driving habits as Greenie has mentioned above, no more than 65. Whenever I can I turn cruise control on, take it easy to and from lights and stops. I consistenly used to average between 22-23 mpg, during the last couple of fillups I have gotten 30, 27, 29 mpg.

TheWeez

I'm averaging 28mpg right now mixed driving with plenty of fast accelerating. Can't wait to see what I get once the header goes on.

CL6

Not to throw too much rain on your MPG parade but I bet the cost of the new headers could probably buy a lot of gas.

The CL-S is a fun car with power... not to use it would be a shame. For loveless high MPG cruising there are always Toyotas.

TheWeez

I'm not getting the headers to try to get better MPG. I want more power. I'm just interested to see what kinda MPG improvement is made. Every little bit helps.

CL6

lol... install a hybrid powertrain i bet you'll get better mpg that way!

RYANGP

True story.