Ideas, tips and tricks to get extra mpg out of a vehicle

What ideas do you guys have to get more fuel economy out of a car or truck? Besides getting it towed everywhere or pushed to its destination?

I think we all already know about inflating your tires to the proper pressure, gettting a tune up, clean air filter, carrying around only what you need no extra junk or weight in your car, no jack rabbit starts and to coast to a stop light incase you can hit the green before you stop. Then the myth busters showed to leave your trucks tail gate up and to drive with the windows up and AC off.

What about the computer chip upgrades for better performance? I understand those also offer an economy mode?

What about lower resistant tires?
Taller tires? Are taller tires good for less rolling resistance?
Higher rear end final gear ratios?

I was reading in a sign industry magazine where if you drive a truck for your job and do not tow, you can use a higher final drive to get up to 5 more mpg. Then the important of using OD, of course i hope everyone uses that.

What about reducing the capacity of your engine? Removing the push rods to a few cylinders in your multi cylinder V block engine to turn off a few cylinders. (Assuming you use push rods, unplug the injector if it has port injection)

What about using or making a body part for the front of your car or truck to make it more aerodynamic? Anyone thought to take a piece of lexan and screw it to the top radiator support and curve it down to your bumper of your truck or car that has a blunt square front end to make it a bit more aerodynamic?

What about those sport wings you see on the rear of cars? Fiber glass and carbon fiber hoods, fenders, doors, etc?

These were just a few ideas off the top of my head.

I'm not sure how smoothly your engine is gonna run if you start disabling cylinders on it. It's not designed to run that way, and it's sure as heck not timed to run that way!

There's a semi-cult movement out there that claims a small amount of acetone added to your gas when you fill up does wonders for the mileage. You can Google up a ton of info about it.

LMU

http://www.tornado-fuelsaver.tv/?so...tornado fuel&gclid=CKfT2tLK_YICFQJnGAodMWVLog

JUST KIDDING!

"What about lower resistant tires?
Taller tires? Are taller tires good for less rolling resistance?
Higher rear end final gear ratios?"

IIRC, the skinnier and higher pressure your tires, the less rolling resistance (e.g. road race bike tires). Also, it is my belief that, all else being equal, taller/bigger tires = larger moments of inertia. If you make that type of change, you May lose mpg in stop and go (around town) and gain mpg in constant high speed (freeway). Changing gear ratios (changing overall wheel/tire size can have the similar but less effect) may also be a little tricky - if you change something, it may not be an optimal match for the output of your engine. IIRC, the higher the rear end, the more the engine will rev at a given speed (but I could be remembering that backwards).

Anyway, YMMV (pun intended)...

Use your cruise control at every opportunity that you safely can. With some careful anticipation I can use it in heavy urban freeway traffic as long as it's not stop and go. I don't use it in potentially slick surfaces, like the first light rain after a dry period, as I've been warned that the wheels could break loose and you would be out of control before you could react.

That mythbusters advice is not very helpful. If it's hot out you're not going to keep your windows up *and* keep the A/C off. I assume the show was about which is better, windows up & A/C on, or windows down & A/C off. I would imagine the answer to that would depend on the vehicle and driving conditions.

Well, what a response. No one here tinkers with their car to get every last bit of distance out of their fuel? ANyone with a manual car rigged up a kill switch to kill the ICE on a car with manual tranny and kill it while slowing or in stop/go traffic?

I think quite a few manufactures have experitmented with engine management systems that would cut off a few cylinders for crusing, using all 6 or 8 for acceleration.

perhaps disconect the injecters on a fe cyliders but cod d i wont do it if i was you it isnt good for car my freind

Whenever I can I try to follow some advice from an old car magazine. Imagine there are eggs under your accelerator and brake pedals, and only by applying gentle pressure will they stay unbroken. This is the best way to improve economy without modifications.

Geoff

Wind up windows, turn OFF aircon, remove those wings/spoliers, tow bars, roof racks. Those can add up to 10% of fuel consumption , i read somewhere. The wings and spoilers (and aerodymanic body kits) are to help high speed (> 65mph) stability and pretty much useless in town/city driving (and in fact adds aerodynamic drag instead). A stick shift is more fuel efficient than an auto. Larger diameter wheels will add weight. Wash your car to remove gunk under the car and wheel arches. Wax the car to have a nice smooth surface for air to flow over. These minor stuff add up. Good luck.

Heh, I like that eggs under the pedal trick. I'm going to have to remember that one.

I was just going to say that the easiest thing to do would be to adjust your driving habits. i.e. Don't do hard accelerations and stops all the time. Anticipate needing to stop so you can coast to a stop rather than slamming on the brakes (and wasting gas).

As for the mythbusters driving with the A.C. vs. the windows, they did that test all wrong. They didn't drive fast enough to get to the point where turning on the A.C. is more efficient than rolling down the windows.

The LLR tires (low rolling resistance) give you 5 - 10 % MPG increase.

The mythbusters report was incomplete. At freeway speeds, the increased drag from open windows uses more power than the AC. AT speeds below 45 MPH, the open windows take less power than the average AC.

There is a simple device that monitors intake manifold pressure and lights a light when there is a strong vacuum. The idea is that a strong vacuum indicates a throttle that's open more than necessary. Even though that may not always be valid, it does teach you to accelerate gently.

The thing about coasting to a stop works with all cars. It tends to make you take your foot off the gas earlier so you save gas that way too. I tend to coast to a stop whenever there are no cars behind me, letting off the gas up to many hundreds of feet before the light.

Daniel

Don't take off a spoiler unless you know why it's there. On the Prius that silly looking spoiler creates the "phantom tail" that helps the car achieve it it's slick .26 coefficient of drag. At slow speeds (under 45) the effect is negligable to nothing. At freeway speeds it makes the car closer to that ideal teardrop shape, increasing milage.

On some cars the spoiler is simply there for visual impact. You have to know which is which before you start to change things.

The "performance enhancing" computer chips claim to know the engine better than teh manufacturer. They often get "better" performance or milage by ignoring some of the anti pollution techniques that the manufacturer has to implement. They are illeagal in California, since they defeat the pollution controls.

Daniel

As said above, DO NOT jack rabbit. I watched my MPG go from 19mpg one tank, to 16 mpg the next tank (well also add in the added weight of hauling stuff around.) I keep the reciepts from ALL my gas fillings and keep track of MPG. I average about 21.8 MPG in a 2005 Mazda Tribute with I-4 engine (2.3 liter Duratec.) This is based on my driving 15,000+ miles in 8 months and using ~628 gallons of gas (I will get the exact figures when I get home.) Most is highway though, don't drive in the city too often. I do the best thing; take public tranist.

$4 round trip for mass transit at ~3 1/2 hours round trip. Driving to school is $48 for parking (~14 hours), ~$14 for tolls, then add in gas costs at $2.65 a gallon (35 miles round trip, so thats about $5 in gas.) That brings the total to approx. $67 dollars for one day at school. Is it worth it? Possibly, I would save an two hours because driving takes approx. an hour and a half round trip. But do I make $31.50 an hour to warrant the extra cost? NOPE. LOL.

Regular maintaince also works well. Tire pressure, oil changes, keep extra weight out, and other things that don't come to mind right now.

If you drive a Suburban, Expedition, Excursion, Tahoe, or any other large type SUV, even gas guzzling sports cars... don't even start with complaining about gas, LOL.

Jason

I used to work in fuel economy. Here are some easy things:

1) Run your tires at their max pressure. If you're in Texas in the summer, back off a few pounds, but otherwise run it at what's listed as max on the sidewall. Worth 1-2 mpg

2) Take everything out of the car that you don't absolutely have to have. That extra 2 quarts of oil, gallon of antifreeze and gallon of washer fluid? Keep it in the garage. Worth 2-3%

3) Make sure your air filter is clean. Worth up to 5% if you really had a crudded up filter to start with.

4) Take any extra crap off - spoilers, bug deflectors, double wipers, etc. Depends on what you had.

5) Run a lower weight oil - ideally 5W20 or 5W30. Worth 2-3%

6) If you drive a manual, lug, lug, lug. That is, shift very early. Hard to say what this is worth.

7) If you can stand it, drive like your grandma. Slow starts and slow top speed. You'd be amazed how much better mileage you can get at 55-60 mph instead of 75-80 mph

8) If you have a pickup, get a tonneau cover or cap. NEVER DRIVE WITH YOUR GATE DOWN AND IF YOU HAVE AN "AIR GATE" THROW IT AWAY. Gate up with no tonneau cover can be 2-3% better than with the gate down, an air gate can be as much as 5% worse. I've had numerous arguments and all I can say is I also used to work in aerodynamics and there are multiple SAE papers which support me on this.

9) If it's an option, get a taller rear end. That is, a numerically lower rear axle ratio.

10) Never buy gasahol or gas with ethanol in it. Ethanol has half the specific energy of gas, so a 10% gasahol mix means you'll get an automatic 5% hit in mileage.

That's all I could come up with off the top of my head. Recalibrating the engine is not something I would recommend unless you know what you are doing.

My dad used a vacuum meter on one of his cars and tried to keep vacuum at highest setting by carefully accelerating. Of course hiw VW Rabbit had the idiot light to tell you when to shift, but if you followed it you ended up wearing the engine out quicker from lugging it down all the time.

I too was totally miffed with that Mythbusters segment. It was just plain stupid. First off, they did the comparison at 45, which is nowhere near the 70-80 I see every day on the highway. Second of all, you would need to have more than a single run of each vehicle to get anything near a valid comparison.

I use a vacuum guage on my '56 Olds. I bought it at JC Whitney. They are also called MPG meters or gas saver meters, among other things. It's really amazing how just a small toe touch on the gas pedal makes the needle jump on one of those guages. With the help of my MPG meter, I've managed to get 21 MPG (highway) out of a mostly stock 324 V8 with 4 BBL carb. Not bad for a 50 year old 2-ton shoebox. For some reason, it gets better mileage at 70-75 mph versus 55 mph. I guess the engine breathes better at the higher rpm. In city driving, it's another story. 16 mpg no matter how I drive. I'd recommend driving in the country as much as possible, avoiding city driving if you have the choice.

twentysixtwo said:

I too was totally miffed with that Mythbusters segment. It was just plain stupid. First off, they did the comparison at 45, which is nowhere near the 70-80 I see every day on the highway. Second of all, you would need to have more than a single run of each vehicle to get anything near a valid comparison.

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They had a follow-up show where they admitted both tests were correct. There is a cross-over point and their first test was above it and the second below it. So at higher speeds windows up and AC on is correct. At lower speeds AC off and windows open is better.

Greg

Use synthetic oil where ever you can. My Tahoe showed a 3hp increase on the dyno when I switched to Amsoil in the differentials and transfer case. That of course proves a significant decrease in friction and could only lead to an increase in MPG. (though I try not to measure MPG because it's horrible either way )

If your car has an automatic transmission

put the car in netural at stop lights etc.

puts less of a load on engine.