Chevy 1500 mpg

[Eric 1]

Well i was checking my mpg on my truck this week and it is about 9-10 mpg!!! now it has a 350 with headers heads and edelbrock carb and intake with a 3 speed auto and stock rear end. is this about right or is there something i can do to make it better. It is expensive to drive man!!

 

[Davis Lawn Mowing LLC.]

Hell, I am looking at the same model. 1500 Extended Cab 5.8 350. Bronzish-gold, almost tan, tan leather interior, bedliner, matching fiberglass topper, power everything ecept seats and 98,000 miles for $9700. I think I can talk the guy down to an even 9 grand though. I hope it gets better gas mileage than that though.

 

[Lawn Specialties]

I have a 92 Gmc extended cab 4x4 with a 350 and it gets 12-13 pulling my trailer in town.Fuel injection makes a huge difference over a carb.

 

[twins_lawn_care]

Eric, that sounds a bit low, maybe there is some adjustment to be made on your carb?
is this while in tow, or any other info you can let us know about.
Sounds like it should be a little higher than 9-10. Now I see why you are looking to swap your rear end out, but that may not be the problem. With the lack of power you seem to be having, and this MPG problem, it may need some tuning up?

 

[The Captain]

Just thought I'd get my nickles worth in....I've got a '95 1500 w/ 175k miles on a 350 V-8 w/ extended cab, 8' bed w/fberglass shell. First of the month I hauled my Turf Tiger, on a 16' single axle, from Little Rock to St. Louis and got 13-14 mpg on the highway. I tried two ways of checking the mpg. One tank I set the tach on 1900 rpm (65 mph+/-) and the other fillup I ran 70+ mph. There was no noticeable difference. I think it's the nature of the beast when they're working. If anyone can squeeze more mpg let us all know. (Unleaded regular went to $1.85 last night in the St. Louis area.) Did you ever wonder why they do it, raise the prices at night?

 

[Eric 1]

Originally posted by twins_lawn_care
Eric, that sounds a bit low, maybe there is some adjustment to be made on your carb?
is this while in tow, or any other info you can let us know about.
Sounds like it should be a little higher than 9-10. Now I see why you are looking to swap your rear end out, but that may not be the problem. With the lack of power you seem to be having, and this MPG problem, it may need some tuning up?

Lets see,
That figure is in tow in town and also not towing, there seems to be very little differance.
The carb is new but it may be slightly out...not that much.
Need a tune up, no the motor is new only about 5-6k on it.

 

[Eric 1]

Captain, You say you get 13-14 on the highway...what about in town.

 

[The Captain]

I've not really checked the mpg in town or city traffic. (I'm really kind of afraid to, now that we've been talking about it.) Just a good guess based on three years would put it at about 11 or 12. Last July I ran to Orlando with the truck empty except for me and 1 suitcase and got about 16.5 as an average for the two thousand +/- mile trip.
I don't think with the rear end ratios in these 3/4 tons we will see much more. With gas prices headed where they seem to be going I wish we could find that secret tune-up.

 

[YardMeister]

I have a '92 GMC Yukon 4X4 with the 350 in it. It gets 18 mpg hiway when empty on a trip usually running around 65 mph, 13 mpg around town pulling my 3k-pound trailer, and average around 15 mpg most of the time for my mix of work and personal driving. It is fuel injected, has the automatic with overdrive, and the higher ratio rear-end. I do wish it had better low-end pull, but having better gas mileage is the trade-off. I’ve used “Mobile 1” synthetic oil in it, since new, and run synthetics in both differentials, the transfer case, and the transmission. It now has 129k miles, and still runs like new. I really enjoy this truck.

 

[twins_lawn_care]

Eric,
Even though the carb is new, it may not have had the correct adjustments on it when it was installed (just a guess, and trying to help fix the problem with lowest possible $ for you)
I'd just double check the idle/mix screws, and float level, should take about 10 minutes, and then you can rule that out, and go from there. Also, possibly double check your timing. You could be blowing a lot of unused gas out of your exhaust, which could be a reason for the low MPG and lack of power.
Just trying to help out with where I'd start. I'd tend to think though with your set up, you should be getting around 13-16 mpg though, as others had mentioned.
Something to think about though, is to just take it in for a gas analyzer test at a local carb shop. May cost about $50, but with the prices of gas now, you could easily save that by boosting your MPG up from 10!
Good luck with it, and let us know if you figure it out.