Gas Mileage

debo4x4 · December 30, 2002

I was wondering why my mileage is so bad. I get between 13.5 and 14 mpg with 75% hwy driving, and I was getting closer to 16 mpg last year. I have only added a FIPK since then but my mileage only seemed to get worse. Any ideas?

sgiangregorio · December 30, 2002

What engine? 8.1? 6.2? I have a 5.3 and get about 15-16 and am actually pretty happy with that.

Shaners · December 30, 2002

My truck always seems to get worse milage in the winter. I don't let the truck idle long to warm it up, so I guess it's just the colder weather. My wifes van gets worse winter weather MPG's too...

colosilverado · December 31, 2002

Have you checked little things like the plugs, fuel filter, etc? I know the plugs are supposed to be good for 100k but alot of guys have been pulling them out and checking them and they are fouled and that type of thing. I'm gonna pull mine ( the plugs) this weekend and check them.

Maybe it is like Shaners said, crappy winter fuel....

TROYROBO · December 31, 2002

I've got a 5.3 in mine--only engine mod so far is a k/n filter--filled up today and got 19.066mpg --this tank full was run out on manly highway at 75-90 miles per hour--but it always is between 17.5 and 20.5mpg

colosilverado · December 31, 2002

Man, that is some killer mileage, troy...

Is yours a 2 or 4 wheel drive?

Mr Dave · December 31, 2002

Check your air filter and oxygen sensors. You might also check your fuel pressure regulator. These are a few simple things that could cause a significant loss in mileage.

ShimanoFisherman · December 31, 2002

I noticed this on my last couple of tanks as well. Dropped a little over a mpg. Went from 13+ to 12. I always fill up at the same Exxon. What's the deal with winter fuel? I thought it might be my tires becoming less inflated b/c of the cold weather but they were in spec.

TROYROBO · January 1, 2003

MINE'S A 2 WHEEL--LIKE I SAY --CAN'T BEAT THE MPG OR THE POWER FOR NOW

Stepside Z · January 1, 2003

My 01 Reg Cab 4.8 Z71 never really got better then 15 to 16 mpg driving on country roads. My lowest was 10.5 just befor I traded it. It had a K&N FIPK and Gibson cat back exhaust.

WEFs99 · January 1, 2003

I'm usually 15-16 but the last time I accurately checked was in warm weather. Our gas gets oxygenated ??? during the winter and I do believe I'm going less on a tank now.

colosilverado · January 2, 2003

I think our gas here gets oxygenated, too. I think I have heard that anyway. I don't think my truck likes it as well.

ClipperSkipper · January 2, 2003

Fuel economy always 'tanks' in the Winter (no pun). Ambiant temperature, winter fuel blends make up two good reasons.

I'm getting 15.9 last two tanks, short trips and some highway.

That's off two mpg from the Summer.

Have a great one!

2000 GMC · January 2, 2003

When we were living in Alaska, my mileage would drop during the winter, 10-13 city. During the summer it would go back up to 14-16 in the city. Same thing would happen to a buddies truck. His was a 98 Chevy with the 5.7.

CapnDean · January 2, 2003

2001 ext cab 2wd 4.8

Winter & Summer I see 16 mpg @ town and 19+ on the highway. I did see 21 mpg once...it was on a long trip and I had been ticketed for speeding during the first 100 miles so I drove the speed limit (gunshy).

I dunno about yall...but I think GM really hit it on the head with the 4.8! Historically I was a 350 man..I always thought that the 305 just didn't have it. I was reluctant to buy the smaller V-8 because I likened it to the weaker of the 2. {E.G. the 5.3 is the 350 and the 4.8 is the 305} I felt that the 305 just did not have the guts that the 350 had...and it did not make up for it in fuel economy either. Worst of both worlds ya know.

I am really happy with the 4.8. Sure it doesn't have the balls of an old 400 small block. But it's good enough to pass on the highway ya know!