I seem to remember that a friend of mine told me a story that he experienced. He was looking for the "Magic" solution to better gas mileage. He swore that a throttle body spacer would work like the advertisemnat stated due to the "Swirling ram effect" and greater atomization of fuel. He purchased it, installed it correctly, (I watched him) and after 2 weeks of driving, he stated he got 1 to 1.5 MPG better! After his exhuberence calmed down, I asked him about his driving conditions. He said he tried to drive the speed limit, did not do the fast starts at the stop lights, drove a more direct and level route, and tried to throttle back on the gas peddle when ever possible. M-m-m-m-m. His aggressive driving ways were changed. After a few months he was back to his old driving ways and I asked him about the MPG. He said the added MPG didn't last and he has not checked recently. The ****n thing stopped working. (I think it's the loose nut behind the wheel)
I installed a Vacuumn gauge years ago on my 2001 Dakota pickup and it does the same thing his throttle body spacer did. It made me aware I was driving too agressive and by keeping a keen eye on the gauge, I saved 1 to 1.5 MPG and $75.00 to boot! My Autometer gauge cost-$45.00. his Throttlebody spacer cost-$120.00. Do the math.
