[69nova]

Since the weather has improved and I have 800 miles on the Monte Carlo, I decided that a check of the miles per gallon is warranted. Filling up after 1/2 tank, I calculate about 12-13 mpg's. Not very good even though the motor is supercharged. Albeit, this is purely suburban, around the town driving so I was not expecting great numbers but it is still 50% off the stickered value (but, then again, is the stickered value for also the non-supercharged motor-one number fits all).
Driving wise, I have been pretty soft with it. You know, the egg under the foot type of acceleration and trying to keep the motor rpm's in the 1500 range.
Also, the exhaust has a whistle to it and can be heard when the windows are rolled up. Since I am a little hard of hearing from being around big equipment, if I can hear it, it must be pretty audible.
I am not going to rush over to the dealer's shop until I gather more data. I suspect that he'll check the emissions sensors, etc. regarding the fuel consumption. I have noticed lalely that the gas gauge seemed to be moving at a frightening pace. So, maybe something has failed/stuck.
Other than that, the car is flawless.

 

[MelvinJ]

Originally posted by 69nova@Jun 3 2004, 12:34 PM
Since the weather has improved and I have 800 miles on the Monte Carlo, I decided that a check of the miles per gallon is warranted. Filling up after 1/2 tank, I calculate about 12-13 mpg's. Not very good even though the motor is supercharged. Albeit, this is purely suburban, around the town driving so I was not expecting great numbers but it is still 50% off the stickered value (but, then again, is the stickered value for also the non-supercharged motor-one number fits all).
Driving wise, I have been pretty soft with it. You know, the egg under the foot type of acceleration and trying to keep the motor rpm's in the 1500 range.
Also, the exhaust has a whistle to it and can be heard when the windows are rolled up. Since I am a little hard of hearing from being around big equipment, if I can hear it, it must be pretty audible.
I am not going to rush over to the dealer's shop until I gather more data. I suspect that he'll check the emissions sensors, etc. regarding the fuel consumption. I have noticed lalely that the gas gauge seemed to be moving at a frightening pace. So, maybe something has failed/stuck.
Other than that, the car is flawless.

The gas mileage ratings are different for a supercharged MC than for a regular 3800 MC.

That is very low, even for around town driving and a green engine, particularly if you are taking it easy. Are you sure you filled up the tank to the same level both times? With such a small sampling (1/2 tank), if the pump clicked off sooner or the car was tilted a different way the second till up, the difference in how full you got it could introduce a pretty big error into the calculation.

I'd run this current tank down to an 1/8 tank and fill up in exactly the same location with exactly the same number of "click offs" from the pump and then check.

If it's still the same, there's definitely something not right.

 

[69nova]

Yes, I took any overfill into my calculations and was on the alert when filling the tank. And I have been driving the MC more cautiously than my Caravans. My 98 Grand Caravan also has a 3.8L V-6 and probably weighs as much or more than the MC and I get much better fuel economy from it. This second fill up will be the official recording since I will be aware of everything.
The tach shows that the motor is running where I would think that it should be forthe speeds.
Since I am also the only driver, nobody else's habits figure into the test.
If there is something amiss, the dealership should pinpoint it and I am not worried since it will be corrected. I should be doing as well as a Pontiac GP since the same motor is in both cars.

 

[69nova]

Whew.
News is much better. I waited until I had only 1/8 tank on the gauge before filling up and I drove the Monte like an old man. The result is 19 mpg this tankful.
This is in the 18 city/28 hwy rating on the window sticker.
I guess that I'll have to stay off the loud pedal if I want the mileage.

 

[Hudson]

Nova:

You do know that the window sticker on new cars includes the rating for THAT particular engine in THAT vehicle, right? The non-supercharged model would have a different rating (and sticker) than the supercharged model.

 

[doh]

In town mileage can vary by SO much that it would be very hard to get an accurate #. Your Caravan is big and kinda clumsy and you don't feel like running the guy next to you to the next set of lights then slaamming hard on the brakes.

Super Chargered shouldn't make a whole lot of difference (about 12% in town driving) over naturaly aspriated. But the spirted feel will make a difference.

HWY mileage is the only true way to calculate mileage, fill the car up till there is gas at the top of the filler neck, on a flat surface, Drive sensabaly for atleast 100 miles at hwy speeds, then refill the same way. The only true way other than the remote jar on the side of the vehicle

 

[flacajun]

if you want to see how they all compare in the mileage wars go here
www.fueleconomy.gov