Are you filling your tires to the tire company's recommendations or GM's?

 

I already have a throttle body spacer on my engine (can't really notice a difference, though). I have a Spectre Cold Air Intake (9901) on order from Autozone, hoping I can kill four birds with one stone with improving gas mileage, horsepower, torque and an airbox/Dorman Oil cooler line conflict (the box rubs against the line. I have some plastic electrical conduit between the two, but I'd hate for those two to be touching anyway...) . I keep the tires inflated properly to between 32-35 and I even have valve caps that tell me when a tire is low. I now use 89 octane gas with Lucas Fuel injector cleaner every 1k miles. I use 5W-30 with 1 qt replaced with Lucas in the engine. I even check the front driveshaft before a long trip to make sure the 4WD is properly unlocked (never had a problem with that, but just to be on the safe side).

On my 18th 180 mile trip home on Friday (with all of the above except for the intake), I was getting like 18-19 highway at like 65 miles per hour with 89 octane gas with the car overstuffed and possibly even overweight with bringing alot of the non-essential and computer stuff from my college dorm room home because in 2 weeks, the semester ends and I don't want to leave stuff there in case I get accepted for a transfer to another college for Spring 2010 (the college I go to had like a 45% freshmen dropout rate in 2007 because it is not nearly as good as it seems (that is one of many reasons why I come home every 2 weeks). Some people don't even last the 1st week. Even though I had reservations even before the first week of the semester, I am not a quitter and I am going to finish out the semester or even the year before I transfer. ). 1/2 the stuff is staying home. The other 1/2 (the computer gear) is essential for the last 2 weeks with final exams and then that all comes home again. I am even bringing my 20 cubic feet roof box up there so I can fit more stuff for my 20th trip in early December. I anticipate gas mileage on the 20th trip will be less than 16 highway with the car heavily loaded inside as well as 150 pounds on the roof (No trailers. Thruway is too fast for them).
Thank god for a nice strong GMC truck that can get me and all my gear home safe and sound.

 

now look into cleaning your throttle body, erg valve, maf sensor, seafoam, exhaust, and a couple other things listed on the mpgs threads. you have nailed most of the things listed, but TBH 16 mpgs fully loaded ain't all that bad for these rides... when was the last time your cooling system and fuel filter got any love?

 

Cooling system flushed in August 2009 (not even 5k miles ago. They WOULD NOT put in the green stuff even after I mentioned an intake gasket leak I had to have repaired. The manager forced Dexcool in my face saying the green stuff "might cause damage" and "we cant do it with green no matter what" and "if you already had the gasket done, dexcool wont hurt it" AFTER it was in the bay with the coolant drained AFTER I specified the green stuff and the other guy said "okay no problem" AFTER an intake gasket leak behind the A/C compressor. Enough "afters" in this sentence?? Also not going back to that Valvoline location ever again. They think they own every car that is in their bay and they don't do a good job. I would never take my car to places I would not recommend my mom take her Lexus RX350 to.).

Fuel filter changed out not even 2 months before that by a different oil change place (my favorite one that is honest. NOT Valvoline.).

All of the fluids on the truck average less than a few months old. I had every fluid that can be changed done over the past year (oil (every 2,500-3000), transmission (next one is 86k, every 15k), transfer case , differentials (going to say every 20-25k), power steering (as needed), brake (as needed), coolant (every 2 years to prevent another gasket failure. next change is with the green stuff even if I have to do it myself.), etc.). Seafoam is the next thing right before I have the oil changed again.

 

I've got a 97 4dr 4x4 with the overhead console that tells me distance left and I can usually get about 260-280 in mine.. If I'm not in the city, that is...

 

well..........my heap is acting like a stupid pig again! she's down to 300km/60L (187/16 gal) give or take 20k (12.5 miles). don't know what the hell is wrong with here.

did the last O2 & Cat just before Christmas, recent cap, rotor, checked plug (re-gap only needed after 40000k/25000miles), fuel filter, air filter surprisingly clean...............

i'll say it again, these 2nd gen's are crap in the fuel economy compared to all the 1st gen's i've had.

 

HA! My old 87 S10 with a 2.8 auto got 10-12mpg while my '01 gets 18+ regularly.

 

I agree with midnightblus10. I normally get 15-16 doing 40mph for about 20 miles every day. But i just recently started getting 12-14 when the snow started and I had to start using 4x4 (on hills and such. I turn it off when it's not absolutely needed). So far, I think the newer blazers get better mpg's. Don't ask me how, but they do. I WISH I could see 18-20 from my blazer...

 

UPDATE: I installed a Spectre CAI and removed the throttle body spacer since the air intake would not fit. Here is my report: While I have seen some improvements in gas mileage in SOME circumstances and a nice change in engine sound, there is a small issue with high speed highway-only trips. About a month ago going back to college for the final 2 weeks of the semester (and my final 2 weeks at that college since I am in the middle of a transfer now), with about 500 pounds of cargo onboard with an empty overhead cargo shell, the truck actually USED 2 more gallons over 180 miles. Usually it is 9 gallons (half tank, usually 19-20 mpg) exact to get the truck to/from college with identical cargo loads. Computer on headliner said 11 gallons exact (16 mpg). Maybe it was the winds since I was driving west for 1/2 the trip or because I had to drive faster this time?? IDK.

The trip home with the truck TOTALLY STUFFED (back seats down with the whole area behind the driver seat full with a couple backpacks on the passenger seat as well as the cargo carrier stuffed) produced similar results, but it used a little less gas surprisingly. Maybe it was the winds coming from the west on the first trip. I haven't been able to do any serious long distance highway-only driving with this truck since I got home a month ago from Utica, NY from college (name of college withheld until my transfer goes through), so when I go to visit my new college (in a small town, but 2/3 the the distance and right alongside another interstate highway, so the trip is all highway driving) in a week or two, I can post realistic updates on gas mileage since the car will be almost empty and with no cargo carriers.

Also since I live in a small town full of hills, I usually get 14 average as soon as I hit the hills, but I can get 18-20 on the main highway that goes through the town. I only drive like 25-30 max with the 4WD engaged in 4HI so I get like 10 or below. I usually don't have to use 4x4 unless it is snowing faster than the town's snowplows can do their work (LIKELY) or if I need to get up our driveway since it only takes a dusting of snow to make my back wheels spin and make the rear of the truck slide off the driveway into the apple orchard (we live on a steep hill so the driveway is raised above the orchard on the right ranging from no difference near the road to like 4 feet steep slope on top. So steep you can't drive on it or if you slide down it sideways, the truck WILL flip).

 

yeah, well my other 'Burb was getting 13mpg as well. so that means this '98 Blazer is s**t for mileage! figure it out, a '90 2WD 1/2 ton 'Burb w/5.7L is getting the same mileage as a '98 T10 Blazer? somehow i think the Blazer is falling up waaaaaaay short.

i beg to defer on that!

my '92 Jimmy was gettng just over 22mpg when i bought it in '96 (173K km/107.5K miles) and by the end it was down to just under 19mpg-and i worked that truck hard.........way harder than i do my '98. so how can the 2nd gen's be better than the 1st gen's?