4.8l Versus 5.3l With Afm

BlackThunder · May 14, 2008

So what's the better choice overall...the 4.8L without active fuel management...or the 5.3L with active fuel management. My naive thinking says getting the bigger displacement for the power...power is ALWAYS a good thing. But nowadays, I have to keep fuel mileage in mind.

akfireman · May 14, 2008

So what's the better choice overall...the 4.8L without active fuel management...or the 5.3L with active fuel management. My naive thinking says getting the bigger displacement for the power...power is ALWAYS a good thing. But nowadays, I have to keep fuel mileage in mind.

I have the 4.8L and its fine for my uses, I dont tow alot, and I get decent gas mileage, I average around 16 most days for everyday driving.

Biggie · May 14, 2008

i went with the 5.3 w/ AFM because they have almost identical fuel mileage but you get more power with the 5.3, it's a total no brainer

98silvz71 · May 14, 2008

POWER!

VMax2007 · May 14, 2008

i went with the 5.3 w/ AFM because they have almost identical fuel mileage but you get more power with the 5.3, it's a total no brainer

I went with the 6.0 w/ AFM because they have almost identical fuel mileage but you get more power with the 6.0, it's a total no brainer

PS You also get a better engine with VVT, 6 bolt mains, better internals, better tranny, ext engine oil and tranny cooling and 4 wheel disc brakes.

slomo007 · May 14, 2008

i went with the 5.3 w/ AFM because they have almost identical fuel mileage but you get more power with the 5.3, it's a total no brainer

I went with the 6.0 w/ AFM because they have almost identical fuel mileage but you get more power with the 6.0, it's a total no brainer

PS You also get a better engine with VVT, 6 bolt mains, better internals, better tranny, ext engine oil and tranny cooling and 4 wheel disc brakes.

I know you love your 6.0 but you really need to stop claiming that you get almost identical fuel mileage to a 5.3. If you do, you truly have a mutant 6.0.

See these 2 polls:

5.3L:

http://www.gm-trucks.com/forums/index.php?...&hl=mileage

6.0L:

http://www.gm-trucks.com/forums/index.php?...&hl=mileage

VMax2007 · May 14, 2008

I know you love your 6.0 but you really need to stop claiming that you get almost identical fuel mileage to a 5.3. If you do, you truly have a mutant 6.0.

See these 2 polls:

5.3L:

http://www.gm-trucks.com/forums/index.php?...&hl=mileage

6.0L:

http://www.gm-trucks.com/forums/index.php?...&hl=mileage

Depends on how you define "nearly". I never claimed it gets as good of mileage as the 5.3. But it does get "nearly" as good. 1-2 mpg less is "nearly" in my book.

I will admit "almost identical" was a little bit of a stretch though. I just plagerized the previous post for effect.

FWIW, I get about 13-14 MPG with 90% city/in town driving. Not many freeway miles logged, but the one roadtrip I took I got 18 MPG but I kept it under 70 MPH and babied the throttle as I was "trying" to optimize mileage to see what max hwy mileage avg I could get. I would estimate typical hwy mileage to be aroung 16-17 MPG.

slomo007 · May 14, 2008

I know you love your 6.0 but you really need to stop claiming that you get almost identical fuel mileage to a 5.3. If you do, you truly have a mutant 6.0.

See these 2 polls:

5.3L:

http://www.gm-trucks.com/forums/index.php?...&hl=mileage

6.0L:

http://www.gm-trucks.com/forums/index.php?...&hl=mileage

Depends on how you define "nearly". I never claimed it gets as good of mileage as the 5.3. But it does get "nearly" as good. 1-2 mpg less is "nearly" in my book.

I will admit "almost identical" was a little bit of a stretch though. I just plagerized the previous post for effect.

FWIW, I get about 13-14 MPG with 90% city/in town driving. Not many freeway miles logged, but the one roadtrip I took I got 18 MPG but I kept it under 70 MPH and babied the throttle as I was "trying" to optimize mileage to see what max hwy mileage avg I could get. I would estimate typical hwy mileage to be aroung 16-17 MPG.

Cool, that sounds about right.

Still not bad at all for a 6.0L beast.

BlackThunder · May 14, 2008

Biggie: This was my thinking...just wanted to see if anyone else shared those thoughts.

If I knew the price of gas was going to come down and stay down, the VMAX would be a no brainer. But as much as I want the power, I do have to start to seriously think of fuel cost nowadays. I didn't know the 6.0L had AFM? I thought it was just the 5.3L.

Vmax2007: What do you mean by the WT gets a better engine? Just looking for more info here...I'm assuming you mean the "work truck" model...you mean it gets a different variant of engine than the higher end models?

MxRider801 · May 14, 2008

Biggie: This was my thinking...just wanted to see if anyone else shared those thoughts.

If I knew the price of gas was going to come down and stay down, the VMAX would be a no brainer. But as much as I want the power, I do have to start to seriously think of fuel cost nowadays. I didn't know the 6.0L had AFM? I thought it was just the 5.3L.

Vmax2007: What do you mean by the WT gets a better engine? Just looking for more info here...I'm assuming you mean the "work truck" model...you mean it gets a different variant of engine than the higher end models?

I think it was VVT or V V T. For me this means variable vein turbo but I'm former diesel guy so I think he means variable valve timing. But, i could be wrong...

VMax2007 · May 14, 2008

Biggie: This was my thinking...just wanted to see if anyone else shared those thoughts.

If I knew the price of gas was going to come down and stay down, the VMAX would be a no brainer. But as much as I want the power, I do have to start to seriously think of fuel cost nowadays. I didn't know the 6.0L had AFM? I thought it was just the 5.3L.

Vmax2007: What do you mean by the WT gets a better engine? Just looking for more info here...I'm assuming you mean the "work truck" model...you mean it gets a different variant of engine than the higher end models?

I think it was VVT or V V T. For me this means variable vein turbo but I'm former diesel guy so I think he means variable valve timing. But, i could be wrong...

V V T = variable valve timing.

2000DV4.8 · May 14, 2008

PS You also get a better engine with VVT, 6 bolt mains, better internals, better tranny, ext engine oil and tranny cooling and 4 wheel disc brakes.

You forgot the 14 bolt SF rear end.

slimjim2525 · May 15, 2008

I would go with the 5.3. I wouldn't necessarily buy into all that VVT stuff either. It's just more components to go wrong. A regular push rod engine is simple. Guess what they use in NASCAR races, used guessed it, push rod engines. Even the toyota motors in NASCAR are push rods.

rogerf · May 15, 2008

So what's the better choice overall...the 4.8L without active fuel management...or the 5.3L with active fuel management. My naive thinking says getting the bigger displacement for the power...power is ALWAYS a good thing. But nowadays, I have to keep fuel mileage in mind.

This depends most on your intended use of the truck. I have the 5.3L AFM & 3.73 which has been more than enough power, but I don't frequently tow or haul heavy loads. Probably would have been just as satisfied with a 4.3L V6 & 3.73 like my last truck. Personally don't believe you will see much difference in fuel mileage between any of these engines. In fact, mine has been accumulating more dust than mileage lately. The savings on a 4.8L will be up-front in the option price.

VMax2007 · May 15, 2008

I would go with the 5.3. I wouldn't necessarily buy into all that VVT stuff either. It's just more components to go wrong. A regular push rod engine is simple. Guess what they use in NASCAR races, used guessed it, push rod engines. Even the toyota motors in NASCAR are push rods.

Um Jim,

My truck is a pushrod engine and it has VVT.