GM's new Active Fuel Management a joke?

[TraceZ]

28 MPG on a new Impala SS

I dont get it. My 12 year old LT1 can do that and it runs on all 8 cylinders all the time. Why spend money on researching this, developing and implementing it for a seriously negligable improvement?

What is the point? What did they gain through all the effort? 1 or 2 mpg? Whoopie.

There are so many simple things the auto manufacturer can do to increase fuel economy. My dad's 2000 Lincoln Towncar is a prime example. It is the "L" Cartier with the factory limosine option and 6 inch stretch between the doors. It is a big, heavy fullsized car. His cumulative mileage currently reads 23.4. According to the car's computer, he gets between 30 and 32 on the highway depending on the grade and wind. He has seen it hit 33 on a long flat. The car sees mostly city driving.

He has done the following:
He keeps 35lbs in his tires
Duralube, Z-Max, and Teflon in the engine oil and the transmission and the rear differential and the power steering.
K&N filter
Magnets over the fuel lines (Fuel Saver)
Cut a hole in the airbox to open it up
Throttle body spacer between the TB and Intake Manifold. It has large cast aluminum fins in it and acts like the "tornado" only better.
Bosch platinum "double spark" plugs

If my dad can get 32 MPG from a 6 year old V8 land yacht with over 50,000 miles on it, what is the problem with the OEMs??? I really dont understand why cars are not getting better fuel economy from the factory.

[casey02ws6]

The biggest reason you get 28 MPG is the 6 speed. I agree with you to a certain extent but you have to keep that in mind.

[Kevin - Blown 95 TA]

He has done the following:
He keeps 35lbs in his tires OK - I buy into this
Duralube, Z-Max, and Teflon in the engine oil and the transmission and the rear differential and the power steering.
K&N filter
Magnets over the fuel lines (Fuel Saver)
Cut a hole in the airbox to open it up This also works
Throttle body spacer between the TB and Intake Manifold. It has large cast aluminum fins in it and acts like the "tornado" only better.
Bosch platinum "double spark" plugs

The rest of that stuff - I don't know...

[TraceZ]

The rest of that stuff - I don't know...

I've been skeptical too, but that computer average doesnt lie. Every time I get in that car and see it I have a hard time believing my eyes.

[Trash man]

thats like my uncles new 3500 crew cab truck he bought, has instant fuel econo. downhills its 99 mpg up a hill its 9mpg. his avg is 19 tho

[Kevin - Blown 95 TA]

I've been skeptical too, but that computer average doesnt lie. Every time I get in that car and see it I have a hard time believing my eyes.

Tracy, next time I see you I'll give you some neodymum-iron-boron magnets that you can put on your fuel lines and see if that works. Then when you get bored with that you can stick them on your oil pan or oil filter to collect metal slurry.

[FroSSty]

I don't think 28 mpg is low for a 300 hp 5.3 V8 A4. I am not too sure about the 18 mpg city though... The best my LT-1 Caprice has ever got was around 22 mpg highway...

I found the following at Limos.com .

"2000 Lincoln Towncar:
Horsepower RPM 200@4250
Torque RPM 275@3000
Towing Capacity 2,000 lbs
City Mileage 18 mpg
Highway Mileage 25 mpg
Displacement 4.6 liters "

[TraceZ]

I don't think 28 mpg is low for a 300 hp 5.3 V8 A4. I am not too sure about the 18 mpg city though... The best my LT-1 Caprice has ever got was around 22 mpg highway...

I found the following at Limos.com .

"2000 Lincoln Towncar:
Horsepower RPM 200@4250
Torque RPM 275@3000
Towing Capacity 2,000 lbs
City Mileage 18 mpg
Highway Mileage 25 mpg
Displacement 4.6 liters "

So, how does anyone explain his combined total of 23.4? His car rarely sees the highway. Maybe a couple hours on the highway every few weeks. Almost all his driving is city. And he does get well over 30 consistantly on the highway as well. 30, 31, 32...

Is his car a factory freak or did his modifications make the difference. He did tell me that his car did not get very good gas mileage when he first bought it.

[Dave M]

Is his car a factory freak or did his modifications make the difference. He did tell me that his car did not get very good gas mileage when he first bought it.

The air in the tires and the K&N/hole in airbox likely made the biggest gains. Although I think the teflon engine oil stuff may be giving better gains than most people give it credit for. If he used it since close to when it was new he's probably really reducing friction there. Same concept as more air in the tires.... reduce friction. He likely added several mpg with his mods.

[FroSSty]

That would be my guess too. So maybe with the same mods on the Impala, you will see the same gains in mpg's? Only one way to find out. So who is going to be the test pig and buy one?

[JL8Jeff]

I would like to know how accurate the computer is regarding the fuel put into the car. I write down every drop of gas I put in my vehicles and also the miles driven between fillups. I think the computers in the cars are off on their gas mileage calculations. And my old 93 Z28 A4 with a supercharger would get 26-28 mpg on the highway so I agree that 28 mpg highway is not that great. I averaged 17.5 mpg with my old 93 and that was putting 42K miles with the supercharger. I live 9 minutes from work and don't get above 50 mph most of the time.

[Joe 1320]

I dunno..... anytime a V8 automatic gets 28mpg it should be considered reasonable. I only see sticks getting better mileage than that.

[TraceZ]

I dunno..... anytime a V8 automatic gets 28mpg it should be considered reasonable. I only see sticks getting better mileage than that.

I guess I had the number 30 in my head as the magical *wow* number and it failed to meet that. Even 30 would of been a minimum.

Maybe as time progresses and they fine-tune the system they will be able to get more impressive numbers. It is a good thing the technology is at least developed and in the consumers hands. Maybe the aftermarket will come up with ways to improve it too. I'd like to see a full sized V8 car rated at 32 MPG highway. I dont think that is too unreasonable.

[thomas]

First off, i dont trust those computer read outs. I dont think there right. I can tell u that on a trip from DE to FL on 1 tank of gas with my 97 ram air 6sp i got 36-37mpg! Most of the time it was in the low to mid 30's. But that was a 6sp.

[Joe 1320]

I guess I had the number 30 in my head as the magical *wow* number and it failed to meet that. Even 30 would of been a minimum.

Maybe as time progresses and they fine-tune the system they will be able to get more impressive numbers. It is a good thing the technology is at least developed and in the consumers hands. Maybe the aftermarket will come up with ways to improve it too. I'd like to see a full sized V8 car rated at 32 MPG highway. I dont think that is too unreasonable.

I do find it interesting that my 93 Corvette Convertible LT1 Automatic with the performance axle ratio still turned an honest 30mpg highway at legal speeds. You would think that some progress would have been made in the last 13 years. I can get that mileage with my 93 Z28 6 speed with a 2.73 rear gear..... actually 31 mpg highway..... better than my 94 3.4 5 speed with 3.42 gears. Go figure...................