I put an aftermarket exhaust on my 2000 blazer and it kill my mpg, its either the lack of back pressure, or my fuel float is stuck.

Highway, with a tall rear end and average speed of around 65, I get a solid 18-19 mpg, on el cheapo regular. No mods, Currently running Blizzaks, 4.3 of course.

For this poll, I'd be interested in the relationship between MPG and if the Blazer (Bravada) is a 2dr/4dr, is 4WD/AWA/2WD, and what the rear-end ratio was.

I'm sure my 4WD, 4dr, with a 3.73:1 rear end will get less mileage than a 2dr, 2wd, 3.08 rig.

For mine I get 18-19 mpg on the highway (60-65 mph) but it drops to 13-14 when I'm towing my sailboat (~2,200 lbs).

I can average 13-15mpgs mixed driving. 17-18 on the highway. Best tank was almost 20mpg coming back from a trip to the mountains (mostly downhill) I drive relatively conservatively and try to be as economically minded as I can with the skinny pedal. 2001 4x4 with 31in all terrains.

I have a 2000 Blazer 4dr, 4wd. I was getting about 19 mpg up until I replaced my MAF sensor and cleared the codes that were making it run in limp home mode. The MAF sensor that I bought was an AC Delco unit from Amazon that they said was the upgrade for the stock unit and had an adapter to get to the correct wiring connection. That was about 8 years ago, and since then I've had great horsepower and am only getting about 15mpg in 2wd. It's less in 4wd. The vehicle only has about 135k miles on it, still mostly rust free, and runs pretty well up to the 96 mph speed limiter for a heavy vehicle at high altitude (9000ft). One downside is that I can only go about 150 miles if I use 4wd, and only about 230 if on a highway trip in good weather, 2wd. I try to fuel it at about 200 in the summer, 2wd. The most that I've ever put into the tank is about 15.2 gallons, usually it's around 13 gallons. I have a hood thingy made out of thick lexan and the window wings which are the same/similar material as well as a roof rack which is the stock type with nothing attached. The window wings are from WeatherTech and I can say they fit really well, were very easy to install and are way better than the ones we had previously which flew off randomly.

Gas Mileage
 

My 89 S15 Jimmy 2WD, 2Dr Auto 4.3L with 7.5 Diff w G80 & 3:08 Gears, Rear Disc, Front Dual Piston Conversion. K&N Air Filter.

I consistently get just over 20.5 miles to the gallon using pure gas. (No Ethanhol)

I average maybe 375km per tank. I only put in 94 octane. And yes.....I cram more gas in; beyond where the pump auto-stops ($3 to $5 worth).

Just did 1,600mi trip. FL to TN and back, towing single jet ski (500lbs including trailer), driving 70-75 most of the trip, with A/C on. . . Yielded 17.4 mpg over the entire trip (90% Hwy). This was also with a plugged up EGR system, so I'm sure it could have been better.

94 S10 Blazer 4dr 4x4 with 4.3 CPI motor. Not sure if they help but I have e3 plugs, RP in the rear diff, and synthetic ATF


**edit - This is also on stock size tires. . .not sure which gear ratio I have

..... Forgot to mention. My driving is about 80% hwy.

This for my basic bare bones Blazer. It's a 3.42 gear ratio 5 spd truck with 4WD. No electric windows, door locks etc. About 70% Highway and 30% stop n go so 17-18 MPG

My ZR2 is closer to 14-15 but it is an auto with bigger tires, 3.73 gears and my options power seats, locks, windows and sunroof