So atm I own an 05 ss sc. Beautiful, but it gets HORRIBLE gas milage. The main reason I passed up an 07 ss was due to the 8cyl vs 6cyl mpg.

I previously owned a 03 jg mc ss, and it got 21 mpg easily, even if I pushed her a little hard every now and then. (She crashed on the LIE because I was an idiot speeding going thru queens x.x)

When I first drove it home, the MPG on the cars computer said 19 mpg. So i figured it was fine. Ive been driving the car for a month now, and im getting a consistant 14-16 mpg.

I changed the air filter(disgustingly dirty; black all around), dropped the back two tires air pressure(I got new tires when I bought the car, and for whatever reason they filled my back tires up to 52 psi) For 32front 34 back. Use only 93 gas from shell, and I drive like a grandpa. I dont like pushing the car over 2k rpm. Friends say I drive slow, people following me always beep and flash headlights at me, etc. Im NOT beating on this car, at all. Im doing everything I can to streach my gas.

Also changed oil from regular to full synth.

Doing these things got me to a consistant 17mpg.

For reference, I live on long island, NY, so its not cold anymore up here, should be less ethanol in the gas soonish.

Me and my dad do all our own work on our cars, apart from trans and internal engine work. We are gonna replace the sparks next week, but what else can we do to tune it up?

Im not looking for 25mpg, and I didnt think a supercharger made the fuel burning go down that fast if, it wasnt really putting out any boost.

Btw, I dont really drive on many highways...but when I did in the 03 it was 27-32 mpg. Now I just hit over 20 mpg on the highway going 55.

 

Best I've seen since I got my 04 was 22mpg, but I can never keep my foot out of it. If you're seriously going easy then something is up.

 

Dirty injectors, bad 02 sensors, mass air dirty and dirty fuel filter might be considered too. Good luck at getting to the bottom of this. High octane fuel is spendy, probably more so in your area too.

 

Yeah gas is 4.50 per gallon over here =c This is actually my fifth car, and nicest yet, and I really want to take care of her. Ive only pushed the gas pedal down hard about five or six times, and none at all on the past three tanks.

From full to gas light being on I get about 200 miles. Filling up at a gas station im at around 240 hoping I make it there, and get about 16 gallons.

I really am being a grandpa to her though, Ive rarely even seen the supercharger boost go past 0.

Since the boost gauge starts at -10, could not pushing her past 0 ever give me worse gas milage?

Oh and also wanted to note, that ive used full system gas treatment by stp twice and it didnt give me much gain.
And would it be bad to try the gumout brand after having stps brand in my tank?

 

Zippy was on the money. I used to have a Dale Jr (Supercharged) and also had a 98 Grand Prix GTP (also Supercharged). The Monte averaged around 32 on the highway and the GTP around 28 (this was due to a bent bar on the rear axle that threw the alignment off. I averaged around 18 in town as well. There's definitely something up and I would definitely check everything out that Zippy mentioned. Good luck! I wish I still had a supercharged Monte!

 

I would deff clean the mass air and put a new fuel filter on and see what that does, I avg 25 in city and 30-32 highway with mine, its N/A but the SC shouldn't be much worse

 

X 2
How many miles are on your Monte ? Does it have any modification to the engine/supercharger ? How many owner's ? (Do you know the past owner(s) ? Do you know `if your Monte has the stock program ?

Keep us updated & GOOD LUCK & Better MPG's

 

My 04 SC SS is averaging about the same as what the others got. About 19-22 mpg.

When I have the snow tires on, I don't even look at the mpg's. Because the softer tires suck up gas like a sponge. Which may also slightly affect your gas mileage. If you have softer all season tires, it may affect your gas mileage slightly. But not that much. Not anywhere near as much as snow tires do.

Mods can affect your gas mileage too. If you're putting more air into the engine than stock. Like if you have a CAI installed for example. The car will put more gas into the engine to keep the air/fuel mixture right. At least that's what I was told when I was considering putting a CAI in.

I'm sure members with CAI's can tell you how much their gas mileage was affected, if at all.

 

I also have a 04 Dale Jr and my gas mileage is not that great. I drive 30 miles one way to work that is mostly highway and I average around 24mpg. My car also has all new tires, plugs, wires, pre-cat O2 sensor, fuel filter, air filter, pcv valve and a Borla cat-back exhaust system.

The best I had ever gotten was 29mpg one one tank when I was going to Georgia on vacation about a year and a half ago.

Wayne

 

84k miles, two previous owners from cali. compltetly stock afaik.