How I improved fuel economy for my car

[AllyCat]

I have a '99 Toyota RAV4. We've all heard that gradual acceleration and deceleration and not exceeding the speed limit will help save gas. I tried this in my mom's new Prius with the on-board computer and doing those simple things made a huge difference in her overall mileage.

So I tried it in my little SUV. Usually, I get between 275-300 miles on a tank of gas and fill up with about 12 gallons at each fill up. Nothing changed with my driving habits this past week. I made my usual trips to work and a few errands. When I filled up, I put in 12.3 gallons of gas and the trip meter posted 345 miles. That's about a 15% increase!

Not only that, I saved money in speeding tickets as I passed two cops in the dark where I usually speed a bit and didn't get pulled over :)

The tires were already at the correct pressure so that was not what did it for me...but that is something else to consider. I think I'm going to hit the auto parts store today and put in a new air filter too.

[EmperorHasNoClothes]

1. Here's a related website:

http://www.hypermiling.com/

I have been trying these techniques and have seen some improvement so far. Alas, it's tough to break 20 years of driving habits. :)

[elocs]

3. Hey, it's tough to break 38 years of driving habits!

I probably don't drive 100 miles a week and my car gets at least 30 mpg, so I increase my fuel efficiency simply by not driving as much--walking or riding my bike. I technically speed nearly all the time (drive faster than the posted limit), but I am not stupid about where and how I do it. I was in Chicago last weekend and frankly, if you drive the speed limit on the expressways, you are a menace. I do have this driving habit from home that is dangerous in Chicago and that is to actually slow down and stop for a yellow light rather than to view it as an opportunity to speed up and breat the red light (there, I do glace in my rear view mirror as I do it). I do have to say after making the 275 mile trip to Chicago on Memorial Day weekend that the traffic on the Interstate highways has noticeably slowed down.

[SomeGuyInEagan]

2. Clean air filter, regular oil changes, properly inflated tires ...

... basic *routine* auto maintenance including tune-ups and care not only improve gas mileage but also cuts down on pollution and greatly extends the life of the vehicle while retaining value. This seems to be forgotten in our throw-away society. Gradual acceleration and deceleration only add to mileage gains.

Our '92 Honda has 240k miles and our '96 Toyota has 190k miles ... both still get 30+ mpg on the highway and should be safe and efficient transportation for a few more years.

[kestrel91316]

4. When I was taking driver ed in HS in 1973 they taught us that

"jackrabbit starts" and driving over the speed limit and slamming on the brakes wasted gas. I guess they don't teach that anymore and folks have to rediscover it independently.........

[CRF450]

14. They still do teach that, kids and many drivers just dont care.

Though I admit I drive almost 10 over the limit, I just accelerate and brake normally, and because my car is a manual, half the time I skip from 1st to 3rd gear.

[Shoelace]

19. in our city, people are driving slower, not doing jackrabbit starts, stops

or so I've noticed in the past week or so. The young ones are still driving fast but I've even seen them driving slower. It has amazed me to see this change.
Relatives in California tell me that nobody is going over 50 mph on the freeways now too!!! That is in Central Ca., near San Luis Obispo but I'd bet it is a trend we'll see more of as gas prices edge up and the word gets out about mileage saved with these slower driving habits.

I'm also relearning the art of "coasting" on slight downhill runs just to see how far uphill I can get with foot off the gas peddle. Farther than I thought!:D

[virginia mountainman]

5. Proper maintenance is key..

You may LOL at me...but what I am about to say is the god's honest truth...

I have a 1991 Ford Explorer, 4x4 with a 5speed transmission. It has 300,000 miles on it. I can get 25 mpg on the open road with it. And yes, I live in mountainous terrain, and my wife is an RN that MUST* get to work in bad weather.

Also, we live half and hour from town, with 2 kids the extra room it offers is EXTREMELY handy.

Not to mention that it has been paid for for well over a decade, and has proven to be an amazingly reliable machine.

*Lives depend on her...

[Lifetimedem]

6. I changed my driving habits a couple years ago

I drove a 1999 Ford explorer and with good driving habits I could get 18 mpg with mixed driving (city/thruway)

Last year I sold that car and got a 2007 Nitro, using the same techniques I get 19-21 MPG in mixed driving

I use the cruise control for any stretch of road that has few or no stops.


I recently read an article that warned many of the "high milage" promise cars require premium gas for that milage, if you use regular you void the warrantee .

So I advise folks to read the fine print in owners manuals before purchase

[pdefalla]

7. Driving habits

Just bought a Prius, replaced my Jeep Grand Cherokee. Went from 12 mpg to 40 mpg instantly (still driving with a lead foot), and now that I have learned to drive more economically (instant feedback from the car's computer shows what works and what doesn't), I'm getting 47 mpg with no real difference in drive time. Just bought gas, here in California its 4.20 per gallon. I miss the Jeep less and less each day.....

[tinrobot]

8. Same here..

Went from 33mpg to 37mpg in my Ford Escape Hybrid just by lightening up on the accelerator.

[trof]

9. Increasing Prius mpg...

Got mine in early November and love it.

The dealer service manager tells me about one customer who brings in Slick 50 for them to add with oil changes. Claims he gets 55 mpg.
I may try it.

Also I've read that if you increase tire pressure to 40 psi you will get better mpg.

[tinrobot]

10. Tire pressure helps... but...

... too much pressure will make the car harder to control, so be careful.

[bhikkhu]

11. Its the contact area that determines rolling resistance

A well inflated tire has a smaller contact area, as does a narrow tire. The modern propensity for wide low profile tire maximizes contact for the sake of cornering performance, etc, in vehicles that have no earthly use for such performance.

If you are thinking about low profile tires or wide tires, keep in mind that the opposite is better for mileage. The old style narrow high-profile tires were better, and still are an option for most cars. Check the load ranges and diameters for best fit, and any good tire dealer should be able to advise (though they make more $ selling low-profiles).

[CRF450]

13. That often makes me wonder what my car would get with narrow're tires

The wheels on my Trans Am are 17x9.5", tire size is 275/45/17. Dont think I could get narrow're tires but the car already averages around 22mpg, and has reached 31mpg on the interstate. Its a performance car after all so it needs the wide wheels.

[tinrobot]

15. It only needs wide wheels for performance driving

If you're driving like Starsky and Hutch, you'd need wider tires, but for normal everyday driving, they're overkill.

[CRF450]

16. Its the factory setup so I may keep it that way.

Though I am interested on getting 18" Corvette rims, 18x9.5" all around, they look good, thats why want them lol. I can go with 275/35/18 tires, it'll keep the outside tire diameter exactly the same as the current tires, that way mpg wont change, as for weight, I'v looked into that, the 18" Corvette rims I'm interest in are actaully lighter, but I dont really expect a change in fuel milage. As for driving use of it, its honestly my daily driver when I dont need the truck but once in while I'll take it to the local drag racing track or to and AutoX track where I can really push it to its limits.

[tinrobot]

17. Do you want economy or performance?

You really can't have both. If you want the wider tires because they look good and you can drag race with them, then that's your decision. But your desire to look good and drive fast is not doing the planet any favors in regards to fuel economy.

[CRF450]

18. I'm aware of that.

Being a car nut, I'd like to do some customizations to the car. I'm actaully saving up for a twin-turbo kit for the car, my goal is 500hp. Believe it or not, the twin turbo kit would actually make it more effecient!

[trof]

12. Yeah, I wonder about hydroplaning.

Seems increased tire pressure would decrease hydroplaning speed.
Not good.

[bhikkhu]

21. Not really, for the same reason that wide tires hydroplane before narrow

A big contact patch spreads out the load over a greater area and allows hydroplaning easier than a small contact patch, which concentrates the load.

Higher tire pressure makes some vehicles more skittish because it decreases the caster effect. The caster angle built into the suspension acts like the canted wheels on the front of a shopping cart: it makes the vehicle more prone to go in a straight line than to steer in one direction or other. The effect of caster varies with the contact patch, less with a smaller patch, more with a larger patch.

[CRF450]

20. I just found something that may be helpful for my truck

I have an 04 Dodge Dakota, 4x4, crew cab. I use it for work and some other stuff, but currently 16mpg with the gas prices as high as they are, its fuckin expensive!! But I found a cool tip that might help a little. It has a clutch fan currently, as far as I know they do put little bit of a load on the engine, I dunno how much though because the clutch on these things do disingage when the vehicle's moving. I found this info on a site specifically for the Dakota and Durangos, they say it shouldn't hurt anything since the truck already has an electric fan that turns on with the A/C or when the coolant temperature reaches 210*.

For some reason the Dakotas with the 5.2 and 5.9 v8's overheat if the clutch is removed, I guess maybe they dont have the e-fan. The ones with the 4.7 v8 (mine) doesn't have overheating issues. Since I'm off tomorrow, I'll probably unbolt it and see if my fuel milage changes.