My truck needs to go in and have the emissions checked. its a 89 d100 with a 318. My grandfather had basically this same truck only his was an 86 and every time he would take the truck in he would dump a bottle of isopropyl alcohol in the gas tank. Apparently some of my uncle's cars that never should have passed went right through after doing this. My question is this, Does the alcohol just help the gas burn better, or is there something else at work there?

 

i could see it helping the gas burn cleaner. i have heard of vehicles failing emissions then the person took the air filter out and took it back in and it passed with flying colors. i know my dad usually runs the higher octane gas in his truck the day he takes his truck in and he makes sure to bring it in hot.

 

Oh yeah. I fail emissions. I fail 'em all day. I'm going to try the same thing this august with acetone.

 

don't use too much acetone. it's not good for plastic

 

I know. When I have used it, I've put in 8oz per 10 gallons. The first time I tried using it, I dispensed it into a plastic cup to pour into the tank. Bad idea.

 

apparently 2-4oz per 10 gallons is suppose to help increase fuel efficiency.
http://pureenergysystems.com/news/20...00069_Acetone/

 

I just finished reading that and I'm actually pretty interested in testing this out myself

 

I've tried it for a mpg improvement, but I haven't actually tested it the right way yet (fill, set trip odo to 0, drive, refill, do math). I can tell you for sure that on my truck, I did not experience a 25% improvement. No siree. Maybe %10 if anything. From entirely unscientific observations, it makes little to no difference in my truck.

 

according to the website i posted a link to if you use too much acetone you actually get worse gas mileage. from the chart they have posted it looks like the mileage started to drop off when they 5oz per 10 gallon or more. 2-4oz per 10 gallons seems likes the best place to be.