what mods will increase fuel economy

[NJP5Guy]

think of it this way. if you drove at 60mph you are doing 1 mile every minute. if you let your car sit and idle for 1 minute you are losing 1 mile per gallon.

 

[Devman]

35-36 highway with headers, intake, exhaust and crank pulley. 87 octane, synthetic oil.

It's all in how you drive.

Devman

 

[wingnut12]

They did a study about the effects of driving with A/C on vs. w/o but with the windows down, and it ends up that the drag caused by having the windows down, is worse than the A/C on. I'd kill for A/C. What was I thinking when I bought my car?

My mileage? 25-27 MPG 90% hwy @ avg of 65-70 MPH, if I figure it all out to american. Just changed plugs, and added a K&N drop in, and the first tank of gas actually got worse. I'm guessing that it's because one of the wires kept popping off the first day (corrected). I'm waiting for the 2nd tank to be sure.

Yes, slowing down would help, but I know I won't. Speed is just too addictive.

 

[rjmhotrod]

I think the real question is how much money do you have to spend to save money? That's essentially what we're looking at. Let's look at a scenario. I'm going to use averages here, so this isn't highly technical but helpful nonetheless. Lets say you drive 15,000/year and you currently get 26mpg. Let's say you're goal is to get to 30 mpg. In your current situation you buy 576.923 gallons of gas per year (15,000 / 26 = 576.923). At 30 mpg you buy 500 gallons (15,000 / 30 = 500). That's a difference of 76.923 gallons of gas per year by increasing mpg by 4. 76.923 gallons at $1.90 (again just an average) is $146.15. So you're saving $146 a year for gas by going from 26 to 30 mpg. If you keep you're car for 4 years then you save $584.60 over the life of your ownership of the car. That's a good amount. However how much do you have to spend on mods to get to that amount. Things I've read so far in this thread include CAI, exhaust, irridium plugs, performance air filters, narrower wheels and tires, higher grade gas, new brake pads, and 4 years of air fresheners (from driving around without A/C on). Granted there were some inexpensive things such as air pressures and driving styles and so forth. My point here is that mods aren't bad but do the math and make sure that you don't spend more on mods than what you will get in return in fuel savings (if fuel savings is your ultimate goal).

 

[chuyler1]

I'm gonna bet that the computer doesn't take enginebreaking into account, and tha tit simply weighs rpms, perhasp throttle position vs velocity...

One of my good friends is a ford master mechanic, and also a fuel economy miser, and he swears that downshifting and engine breaking will either cutoff or atleast greatly cutdown injectors, and it WILL have a positive effect on your gas mileage. Granted this is only going to be the difference vs whatever idling for the length of time your braking down to speed would take, but multiply that by however many stop and go cycles you have, and it adds up. Hell I'm suprised noone's mentioned turning off your engine at long stoplights, essentially that's the same thing. Again, this is with your car idling, so it's not a HUGE amount of gas, but it will add up. I know for a fact form excessive laziness and remote start use that a car idling for 5-10min every morning will dip heavily into your mileage.

Even the 2-3 minutes while you scrape off your car on a cold winter morning will make a difference.

Engine braking is another reason manuals get better gas milage. In an automatic when you take your foot off the gas, many times it will shift to a higher gear and idle allowing you to coast much farther which usually results in more frequent braking. With a manual, even if you don't shift, you will feel the engine begin to brake the car as soon as you release the gas pedal.

 

[chuyler1]

I think the real question is how much money do you have to spend to save money? That's essentially what we're looking at. Let's look at a scenario. I'm going to use averages here, so this isn't highly technical but helpful nonetheless. Lets say you drive 15,000/year and you currently get 26mpg. Let's say you're goal is to get to 30 mpg. In your current situation you buy 576.923 gallons of gas per year (15,000 / 26 = 576.923). At 30 mpg you buy 500 gallons (15,000 / 30 = 500). That's a difference of 76.923 gallons of gas per year by increasing mpg by 4. 76.923 gallons at $1.90 (again just an average) is $146.15. So you're saving $146 a year for gas by going from 26 to 30 mpg. If you keep you're car for 4 years then you save $584.60 over the life of your ownership of the car. That's a good amount. However how much do you have to spend on mods to get to that amount. Things I've read so far in this thread include CAI, exhaust, irridium plugs, performance air filters, narrower wheels and tires, higher grade gas, new brake pads, and 4 years of air fresheners (from driving around without A/C on). Granted there were some inexpensive things such as air pressures and driving styles and so forth. My point here is that mods aren't bad but do the math and make sure that you don't spend more on mods than what you will get in return in fuel savings (if fuel savings is your ultimate goal).

Good scenerio. I remember posting a while ago the cost benifits of a hybrid car. Going from an SUV that gets 10-15mpg to a hybrid is a worth while investment but trading in your Protege or other gasoline compact car that gets 25-35mpg for a hybrid that gets 40-60mpg does not ease your wallet very much. If you buy one to save the environment that's another story.