hey guys,
2000 v6 w/100000 on the clock, i did a major tune on it, all filters even tranny, all fluids even diff's,transfer case, plugs, wires,cap,rotor, seafoamed it,temp sensor,tps,changed,flushed/filled coolant.... I'm getting about 10-11 mpg !!! it runs new, why am i getting such lousy mileage, even drive'n it easy.. any ideas?

 

It's a Blazer. Lol to be honest gas mileage on them is terrible. I was getting 12-13 when I first got mine. A K&N air filter helped to get about 1-2 mpg's more and I started running synthetic oil and that got me 2 more so I got to about 15 driving it nicely. I added a cold air intake and that got me 2 more miles per gallon. So driving like a normal human being I get 17-18 miles to a gallon and 15 driving like an idiot. Happens when I'm late for class. So I'd try doing little stuff like that and hopfully it'll help. Also, watch what kind of gas you put in it. I went to loaf and jug once and my mileage dropped from 17 to 14. I used 87 octane. So try Shell or Exxon. Those are the two big companies in my town, so I don't go anywhere else and there is no texaco or chevron or anything. I love shell 87 so try that too.

 

Be sure and use Unleaded and not 10% ethanol. You'll increase your mileage at least 10% by NOT using ethanol gasoline.

 

Have you tried different fuel stations? I see a large change in fuel mileage between the local stations. The local discount sources (BJs/Walmart) also do not produce the best mileage in my experiences with my old Bravada or Bonneville as well as my current Rainier.

Do you have different tires? I saw a decrease of 1.1MPG (consistent) when I changed the tires on my Rainier last October (comparing May thru October of last year with those same months this year). I went with a different brand of tire which was of a heavier construction than the original Michelin Cross Terrain SUV.

Says who? My Bravada experienced no drop in fuel mileage when NY made the switch. My Bonneville actually had better mileage with 10% ethanol blends. My experience though.

 

Yea I didn't see a drop when NC went E10 either.

If youre really that low, first look at your driving habits (short trips, high idling, etc will kill your avg mileage). If youre ok there, its very possible you have a fuel leak! Does your exhaust smell any thicker of gas than any other car youve been around?

 

Most if not all got that ethanol around here in Ct. I have stock Goodyear tires & rims (up to proper inflation), But, I notice I get alot of condensation when I first start it up, wondering if possibly head gasket or intake manifold gasket with a small leak? the coolant says full though. Is the timing really not adjustable? I cleaned the mass air flow sensor too, k/n air filter. that's why i wonder if there's another temp switch that goes to the ecm, telling the when the vehicle is warm, i changed at the block for inside gauge. Any more ideas will be helpful, Thanks Nick

 

Timing is handled by the PCM and is not adjustable.

The temperature sensor in the side of the block is the only sensor on the newer motors. The gauge is fed information from the PCM. The older motors with the single wire temperature sending units were the ones that had another temperature sensor for the PCM.

Does the exhaust smell slightly sweet which could be an indication that you are burning coolant... I will say that condensation in a cold exhaust system is fairly normal. So long as it is not a stream of water coming out of it, you should be fine.

 

No, I cant say it smells funny, but back to the coolant sensor the one i changed had 2 wires, when i pulled the connector the gauge went down. It seems as your the best in question answering this forum, there gotta be something goin on here, my silverado 5.7 had better mileage !!!!!! What's the unit/part next to t-stat housing on the intake mounted into the intake? it has a 5 wire connector in it, its about 3' in diameter?

 

See now, this is why it is best to keep everything listed in one thread. You have not seen my response to your other thread (CLICK HERE). I believe what you are talking about is the EGR valve which has nothing to do with the cooling system. If the EGR valve is clogged, it could reduce your mileage.