what do you do to get the most mpg in your truck - Page 3

Originally Posted by landmine

No way drafting will make your rpms go down.

Tire spins a fixed amount for any speed, follow that to the rear end gears, to the trans to the engine.

NO way to change the gearing
Just the amount of work needed

Here is a quote from the link I posted; When your getting 40% less drag on your vehicle you are using less throttle to maintain your set speed. Less throttle equals less RPM.

Jeff has mentioned hypermiling here and here; it is the sport of squeezing a gallon of gas until it screams. One popular technique is drafting, or driving really close behind big rigs to get into the low-pressure zone created as they move through the air. According to Discover online, driving in this "free ride zone" not only save fuel for the tailgating driver, but also for the trucker, who is getting a little high pressure push.

Until something happens. Tim Haab at Environmental Economics shows test results from Mythbusters:

* In scaled wind-tunnel tests, driving 100 feet behind a semi at 55 mph will reduce drag on your car by 40%. The drag reduction increases as you approach the bumper of the truck until you get a 93% drag reduction at a distance of 2 feet.

* In road tests, the testers achieved an almost 20% improvement in gas mileage at a distance of 100 feet (at 55 mph) and a 45% improvement at 10 feet.

Tim also calculates that at 100 feet you have 1.25 seconds to respond if the truck slams on the brakes, (keep off that cell phone) and at ten feet you have .124 seconds. The recommended distance at 55 miles per hour is 150 feet.

Conclusions: there are better(safer) ways to save fuel.

Originally Posted by Mechanic688

Here you go, they help explain all the quackery;
K&J Magnetics - Fuel Magnets

Reading that, they don't sound too sure of it themselves, but of course if someone wants to buy something you can make there is no reason not to, haha. To my understanding though, the nature of hydrocarbons such as gasoline renders them essentially "non-polar," which is why they separate from water (which is polar, meaning that each molecule has basically a positive and negative end). To me it doesn't make any sense... Is there anyone that can direct me otherwise?

Originally Posted by wannabemechanic

Reading that, they don't sound too sure of it themselves, but of course if someone wants to buy something you can make there is no reason not to, haha. To my understanding though, the nature of hydrocarbons such as gasoline renders them essentially "non-polar," which is why they separate from water (which is polar, meaning that each molecule has basically a positive and negative end). To me it doesn't make any sense... Is there anyone that can direct me otherwise?

If you want to try it yourself the take a pair of hard drive magnets and duct tape them to the metal fuel line going to the engine. Put one on top and one on the bottom. That way your not out any money on the experiment. Might have to use a hose clamp instead of duct tape.

How about...cold air intake...ported throttle body...tuner

how is a fuel line magnet gonna work when 90% of people dont know the diff between the supply and return line, just saying

Originally Posted by jghilino

how is a fuel line magnet gonna work when 90% of people dont know the diff between the supply and return line, just saying

That's why I posted that one link, they don't promote the magnets, they just make and sell them cheap.
Back in carburetor days we used to add a spacer underneath and put a piece of screen wire in with the spacer. It would help break up the fuel molecules so they would blend better with the air and burn the fuel better and more complete.