ok here is the low down..lol...i have a 2000 chevy blazer ls 4 dr 4.3l v6 vortec....the truck is completely stock besides the tires...they r 30x9.50 BFG....i have owned it for 3 years and some months....and i am gettin some crappy gas mileage....im gettin like 11 or 12 miles to the gallon...is that normal for these blazers....or could there be something wrong...it runs perfectly fine....never once has shown a check engine light....i never tow anything with it....i never dog it or run it fast....95 percent of the time it is city driven....never use 4x4...and its a automatic...please let me know if anyone else is gettin the same gas mileage....thanks for ur time

 

1 more thing it has 80000 miles on it

 

well, a few things.

1. know this sounds stupid, but make sure its in 2wd
2. you could be fouling spark plugs, so check plugs, wires, dist and rotor
3. Could be clogged or overspraying injectors. clogged fuel filter you could be just dumping gas and its not being detonated.
4. Air Filter
5. and maybe the gas gap. apparently 147 million gallons of gas are lost through evaporation.

 

yeah its in 2wd....gas cap is fine on it...if the plugs was fouling wouldnt it run ruff?....mine runs great..idles perfectly...no lost of power at all and the air filter is new...not sure about the injectors though....i guess i can take it to the shop and let them look at it...any other things it could possibly be?...and wouldnt the exhaust have a smell if the injectors was throwing out to much gas?....exhaust is fine and there is no hole in the tank either...lol....

 

i was down a cylinder, and I could barely tell by the idle. maybe )2 Sensor, fuel pressure regulator.

 

another thing is keeping the air pressure correct. if the air pressure gets low, it increases the rolling resistance, and reduces your gas mileage. also, you said 95% is city, how much time do you spend idling at stop lights? Idling uses up quite a bit over the length of a tank of gas.

 

thanks for the help guys....im parking the blazer...im going to buy me a honda

 

I had the T-stat stick open on mine and the truck would run about 160F. This caused it to stay in the "choke" mode all the time.

Changed T-stat and put Seafoam in the crankcase. Last check was 18.9MPG

 

I've got another vote for O2 Sensors. If you do replace the upstream sensors (on the y-pipe off each exhaust manifold), replace them with AC Delco sensors ONLY. I have had nothing but bad experiences with Bosch (both direct fit and universal), Wells, and Borg Warner. All of them, when compared with an AC Delco sensor, were lazy out of the box.

When I did my tune up on my Bravada consisting of plugs, wires, cap, rotor, pcv valve, EGR cleaning, throttlebody cleaning, and O2 sensor replacement, I went from 11-12mpg to 17-18mpg consistently. Now the plugs weren't all that bad, but if I'm replacing stuff, I'm not going to skimp. Cap/rotor were worn pretty bad and had carbon buildup on the terminals. Wires weren't bad, but could see some abrasion on one of the wires so they got tossed. PCV valve just because. New EGR gasket. Can of sensor safe carb cleaner. AC Delco O2 sensors from the local AC Delco retail store cost me $75 each. Total cost spend (not including the crappy Borg Warner O2 sensors I purchased) was ~$275 all done myself. The increase in fuel mileage by +6mpg at today's gas prices(~$2.90/gallon) will pay that back in alittle under 3500 miles.

I do have to agree with cherry. If it's 95% city... Even a honda will get crappy mileage for a honda with 95% city driving.

 

hey......that's crappy mileage..I have the same truck as you....with 111,ooo miles.......I used to get horrible gas milage....now I get 18-22 ....(22 on a very very good long distance drive day) I found out my front axle was always engaged even though it wasn't in 4wd....my transmission blew...and when they were fixing it...that's when they found it....I don't know what they did.....might be something to have someone look at...now I get great gas milage....it ran perfectly...I always complained about the gas milage....like I said...I don't know 100% of what they did....but it worked...