85 SS Fuel Economy

I recently bought an '85 SS. It has just under 116,000 miles, and is all original, including the 305 engine. It runs and drives great, but it uses alot of gas. I looked it up on http://www.fueleconomy.gov and it says that it should be getting 17 mpg city and 24 mpg highway. I tested it myself because I knew it was using alot more than that, and it came out to be using about 11 mpg, mostly city driving. I put a K&N filter in and it went up to about 11.5 mpg. I plan to keep it pretty much in it's stock form, but I need some tips on how to improve on the gas milage. Are there any products that I could install that would help?

have you done a tuneup yet? if not replacing all of the basic items such as cap, rotor, spark plugs, spark plug wires, fuel filter, inflating your tires to the proper psi, and even changing oil will make your car and engine run more smoothly and efficiently. As for specific products? I don'y know if there is anything in particular that will give you a big mpg boost.

The guy I bought the car from said he recently had a tune up done; he had the car since '88 and kept it up very well so I believe him. But the car is due for an oil change soon. I was wondering if changing the stock air cleaner assembly would help? Besides being ugly, it looks like it doesn't let much air in through the opening. I'd like to install a billet air cleaner that exposes the air filter because that seems to let more air in, not to mention it looks much better. But there is a pipe/hose that runs from the bottom of the stock air tube to the exhaust manifold. If I were to upgrade the air cleaner, how would I deal with that? And, has anyone tried the Tornado or Turbonator? I've seen ads and wonder how well either of them works.

The guy I bought the car from said he recently had a tune up done; he had the car since '88 and kept it up very well so I believe him. But the car is due for an oil change soon. I was wondering if changing the stock air cleaner assembly would help? Besides being ugly, it looks like it doesn't let much air in through the opening. I'd like to install a billet air cleaner that exposes the air filter because that seems to let more air in, not to mention it looks much better. But there is a pipe/hose that runs from the bottom of the stock air tube to the exhaust manifold. If I were to upgrade the air cleaner, how would I deal with that? And, has anyone tried the Tornado or Turbonator? I've seen ads and wonder how well either of them works.


first off, don't get a tornado. i've heard only bad things about it. Secondly, as odd as it may sound oil does play a small part in mpg. The cleaner and more pure the oil, the more free the engine can turn. If its all crappy and sludged up, the engine is gonna have to work harder. Also, yes adding an open air cleaner will increase mpg. As for your hose that goes to the air cleaner, this is part of emissions. A small part of the exhaust goes back through the airflow. IN the air cleaner, there is a small foam piece that filters the exhaust before it hits the air filter. Like most emissions on the monte carlo, it plays only a small role and should not have an impact on how your engine runs. You could probably just disconnect the hose and plug up the part on the exhaust manifold, but that is up to you.

Thanks for the info. What could I use to plug the hole in the manifold? I'm changing my oil today so hopefully that will help. I love the car, but the gas is too much.

If you were really serious about getting good gas mileage you could change the gears in the rear end, stock they came with 3.73 at least thats what mine has

Well, I installed the Tornado, and changed the oil. I'm now getting just over 13 mpg. I don't know which worked (Tornado or oil change) but it helped. If I could get it to at least 15 mpg I'd be satisfied.