Gmt 900 5.3 Gas Mileage Poll Afm

[crepitus]

Please vote only if you have a 5.3 4x4 GMT900 AFM with 3.73 gears.

 

I was curious what you guys with the with the GMT 900 AFM 5.3 are getting for fuel mileage. I am only concerned with 4x4 truck so I can get an equal comparison to what I am getting. For some reason I think my mileage is horrible. I average about 14 around town. My wife just got back from a 800 mile trip with it and she averaged 16.5 mpg. I think that it should be alot better then that. I am going on a 300 mile trip Friday. I will see with my driving style if I can get any better.

 

I know there was a poll like this a while back but I wanted a more specific to my truck poll.

[Nick The Great]

That's all the lower your poll goes?!?!?

 

I have a 4WD GMT900 with the 5.3L and AFM. But I burn E85, so my mileage is lower.

 

I get 11 in town and at 80mph on the Interstate. When I checked with regular gas, I got maybe 12.5 (in town).

 

I don't really have any driving that I do 55mph on.

[matt3]

Mine's a 2wd so I didn't vote.

 

Your around town mpg's are about right. I bet if you babied it you would get a little better (maybe). The highway mpg are a little low. For a 800 mile trip I would expect in the ball park of 18 or 19 but, that all depends on the temp, terrain, wind, and your speed.

[Stevens03]

Hell, I get better than that with my 6.0 with the AFM turned off.

[crepitus]

Hell, I get better than that with my 6.0 with the AFM turned off.

i am considering turning off AFM

[BuckFeverZ]

16-17 here with AFM off.

[J-man67]

no 8-10 option?? I got pretty decent mileage before the lift and crap. I got about 15 city, 18-19 highway.

[VMax2007]

no 8-10 option?? I got pretty decent mileage before the lift and crap. I got about 15 city, 18-19 highway.

 

Damn Justin, having a tiny penis must be expensive!

[geektoad]

16-18 combined here. It I have to baby it to get 18. It's usually closer to 17.

[mhenshaw]

I usually get 16.5 on the highway running 75-80, but if I go 65-70 I can average 17.5 Normally with 50/50 city/highway I get 16 mpg.

[J-man67]

no 8-10 option?? I got pretty decent mileage before the lift and crap. I got about 15 city, 18-19 highway.

 

Damn Justin, having a tiny penis must be expensive!

 

 

Hey, lifting the truck was cheaper then the surgery!

[gdpgmc]

Most of my driving is 60% city, the DIC says about 17.5. I know that is about .7 too high according to real world. I voted in the 16-17 range. I am checking the "real" mileage again on this current tank.

 

I know that if I drive no faster than 65 on the highway I can get over 19. I live in the northeast, and did a airport pickup a couple of weeks ago to NYC. Because of traffic I was forced to stay between 60 and 65, and being a "normal" driver I was watching the AFM and I it stayed in 4 cyl mode more often than I thought. DIC showed over 20. I-95 is pretty flat which helps. I do know if you go over 65 the mileage drops.

 

I read alot about likes/dislikes about it(AFM), people turn it off, whatever.. Hey, its your truck, do what you want. but I know it helps me definitely on the highway.

 

On the city roads, it can help slightly ONLY if you work with it. but the paybacks I believe are small and completely outweighed if you drive heavy footed.

[Bowtie2Sierra]

The best I have ever gotten is 20.8 hwy with a 30mph tail wind running 93 octane. Normal conditions...I get in the 16-17 range between city/hwy. All highway going 75 and I'm around 18.5 on a good day. City I'm usually around 16 b/c the city conditions in which I drive are condusive to AFM staying in 4 cyl mode quite a bit. I have the BB 91 octane tune so I run either Shell 91 or 93...I noticed about a .5-.8 mpg increase since my truck was tuned for 91. Not sure if that was due to the BB tune, octane or both.

[bubba33]

The best I have ever gotten is 20.8 hwy with a 30mph tail wind running 93 octane. Normal conditions...I get in the 16-17 range between city/hwy. All highway going 75 and I'm around 18.5 on a good day. City I'm usually around 16 b/c the city conditions in which I drive are condusive to AFM staying in 4 cyl mode quite a bit. I have the BB 91 octane tune so I run either Shell 91 or 93...I noticed about a .5-.8 mpg increase since my truck was tuned for 91. Not sure if that was due to the BB tune, octane or both.

 

 

Are you hand checking the mileage or going by the computer. The reason I ask is that there are some tunes that used to make the DIC readings off.

[fbachman]

Please vote only if you have a 5.3 4x4 GMT900 AFM with 3.73 gears.

 

I was curious what you guys with the with the GMT 900 AFM 5.3 are getting for fuel mileage. I am only concerned with 4x4 truck so I can get an equal comparison to what I am getting. For some reason I think my mileage is horrible. I average about 14 around town. My wife just got back from a 800 mile trip with it and she averaged 16.5 mpg. I think that it should be alot better then that. I am going on a 300 mile trip Friday. I will see with my driving style if I can get any better.

 

I know there was a poll like this a while back but I wanted a more specific to my truck poll.

 

I monitor my mileage via recording odometer and gals at fill up. I always fill to the first click on the pump. I average 14 around town / suburban driving.

 

On trips, averaging 80mph, I have done as good as 19-20, usually in the 18-19 range on the super-slab.

 

With summer blends, I do a little better than that, with winter blends a little worse. Averages 14-15 overall around town. I am not too much if a lead foot, though, on occasion, like to listen to the CAI and make sure it still sounds as good as it did last week.

 

If folks are reporting mileage based on DIC-displayed results, they are, on average, 6%-7% optimistic (based on my data). DIC always reads 6-7% too high on mpg.