OT Sierra Gas mileage

HTH
Aaron

When Chloe-baby starts complaining about buying gas, I know it's time to pull the camino's EGR apart

Good luck, Dave

Fill it up, write down your odometer reading. The next time you fill up, write down the odometer reading. Now figure you gas mileage. Because different gas stations' pumps are set differently, more readings will give you greater accuracy. For most purposes those 2 readings will tell you what you want to know.

Maybe the whole problem is the kind of driving I do.

I drive mostly

Short trips under 5-45min usually less than 1/2 hour.

Its unusual if I dont stop or change speeds with in 10 miles

I drive between 40 & 60 mph, never constant especially on these roads changing from 40-50 a few time a mile is not uncommon.

I'm 16 years old and am the only kid that I know that drives like they should and have never done anything stupid in this truck. truck has never seen 65 (me and a buddy had a bad rollover accident which we walked away from, going 40mph.) We were driving safe and responsible, car went over the center line arround a slight turn he got scared put it in the grass and fish tailed it.

Some things to consider:

If the tires and wheels are not original (are oversize), the speedometer and odometer need to be recalibrated. Otherwise you could be driving a lot more miles than are indicated. Check your odometer over a measured mile.

The transmission needs to shift into overdrive and the torque convertor needs to lock up for best mileage. That won't happen until the transmission has warmed up and you're going at least 45 mph. Short trips or driving below 45 isn't going to give you good mileage.

Check out your brakes to see if you have a hot caliper. You could have a dragging brake.

Chances are your fuel gauge isn't accurate. Top off the tank, drive at least 200 miles then refill to the top. That will give you a decent average.

I think to need to figure what your fuel milage actually is - before looking for problems. With your 4.3, it could be throttle-body injected, or central-port-injected. With the latter CPI - with VIN-code W trucks - they are known for breaking fuel lines under the intake manifold and then becoming gas hogs. If throttle body - and it seems to be running good, the O2 sensor is the first thing I'd check out. With a bad sensor, it can run perfect but have fuel mileage drop 20-30%.

Fill it up, drive your miles, fill it up again. Do the math.

I find the better mileage on premium fuel more than offsets the extra cost. I keep a running log on the pick up and can see in heart beat when it drops off.

I will pick up 4-5 mpg more running on a trip, cold starts really hurt the efficiency.

Run synthetic in engine and transmission to gain 2-3 mpg.

SiL has a 4.3 in a 1500 and doesn't get any better mileage than my 6.0 in a 2500HD. Gear ratios have a lot to do with it, and 4WD will drag it down too.

11 is low, but but not horribly so. I get around 14, SiL gets maybe 13 on a good day.

Sucks, doesn't it?