newb question on gas mileage

[BeechStreet]

I have an 88 PU w/ the 22R and noticed the muffler was practically falling off from rusting through so bad. This morning I removed just the muffler and my friend told me that my gas mileage is going to take a steep drop. is this true? i really dont want to spend the cash on getting a new muffler welded up, since this is my beater truck. thanks.

[87_SR5]

Originally Posted by BeechStreet

I have an 88 PU w/ the 22R and noticed the muffler was practically falling off from rusting through so bad. This morning I removed just the muffler and my friend told me that my gas mileage is going to take a steep drop. is this true? i really dont want to spend the cash on getting a new muffler welded up, since this is my beater truck. thanks.

I am not sure, but I would think removing the muffler would eliminate the restriction on the exhaust system....allowing the engine to get rid of exhaust gases easier so it wouldn't have to work as hard. (just the same as installing a header on your engine...gets rid of the restriction that the stock manifold had, allowing for better escape of the exhaust, improving power and mileage)

Other than it being noisy, I don't think your mileage will suffer....

I could be wrong though. I am sure someone else will have a better explanation.

[WhiteRabbit]

i would guess the opposite effect would take place, improving mpg like how a muffler should do.

^basically what he said

[amber00dak]

might loose a little cause of the lack of backpresure, but nothing major like your friend said. if you do alot of highway driving, it might improve. if your in alot of stop and go, you might hurt a little cause ya might have to rev a little higher to get it moving each time cause the lack of pressure. nothing too major other than the noise, i wouldnt really worry about it especially if its a beater. even if it does go down, whats a couple MPG less per tankful

[crazycruzer]

Mufflers are installed on vehicles for 2 reasons: reduce noise and provide back pressure. Since your truck does not produce high horsepower or torque, your loss in back pressure will have little affect on your gas mileage. Spend your money on a nice set of headphones.