Hi, I commute 120 miles one way to work. If I go to work and get to go in the office all day and then drive home I can make it on a full tank. Get like 240-260 Miles to a tank. My problem and couldn't find any thread really dealing with how to possibly get better mileage idling. Most days I spend 8-12 hours idling on construction projects. I need to stay idling for AC and to run several 12v accessories without killing battery. So any pointers or possible things I can try to get better usage of gas during idle time. I go through half a tank idling 8-10 hours. Getting crazy expensive. I do have a service engine soon light on, that I need to have checked, but the mileage i get actually driving seems decent for the vehicle.

Thanks for any input!
-Mike

Probably should add its a 97 4wd, 4.3 vortec. 186k miles. 60k of those miles put on in last year. Runs good can't complain about anything but the gas it uses idling. Its stock, no aftermarket anything on it.
-Mike

No matter what you do, your mpg while idling will be 0 since you are not moving. Just make sure the engine has a complete tune-up (distributor cap & rotor, spark plugs & wires, fuel and air filters, clean MAF sensor) and run a couple of gas tankfulls with Chevron Concentrate Plus cleaner in them to clean the fuel system.

There is really no good way to reduce fuel consumption at idle (beyond tune up, etc to get it operating as intended) without really fiddling with the tuning and I'm not sure what is even available in the '96-'97 PCMs. Even then, you aren't talking about mileage as Rich has stated, just efficiency. Cutting back on the power needs being asked of the engine would be the best & easiest way to improve the fuel efficiency.

Might want to look into adding a couple accessory batteries. That way they can drain while you run the accessories you need (no a/c though) and you'll still be able to start the truck and drive home. Not sure if you'd have to add another (or higher output) alternator to do something like that, but short of turning the truck off, you won't be able to do a whole lot else past a tune up.

Fighting the same war! 100 mi per day! I am lucky I live in flat land and an averaging almost 23 mpg-but that is STILL $12 a day! The best I have ever achieved out of this unit was 25.5-again,flat roads... Not much you can do besides the usual tweaks!

What sort of accessories are you running? At the cost of fuel, you may be able to come up with an alternative power source. If youre willing to part with the AC for at least part of the day, An aux power source for the other equipment may pay for itself in a short time!

i would have to suggest that you do get a extra battery or two, build a couple boxes for them, mount them in the back of your blazer and route them to your accessories. If the accessories are stand alone and not connected with the truck, then you won't even need to mount the batteries in the back. Or use a fellow construction workers vehicle to run those accessories from. Im not electrical engineer or scientist but i figure, a battery has constant power running (or stored) in it, so by hooking up the positive and negative wires from accessory to the battery terminals, would be sufficiant to run those accessories.

Since you won't be using the battery to actually start the vehicle, it should be fine as a stand alone as long as it is top post. I think you might be able to use side terminal as well, just use 2 bolts to screw into the battery and wrap the wires around the bolts. It might need grounded though, which shouldn't be a problem either just drill a hole somewhere thats bare metal and hook up a ground cable to it. Thats IF it needs grounded, which i don't think it does.. but i could be wrong. I know this seems out of left field, and you probably won't bother trying it, but think about it like this.. you take a C battery (the one that has the two prongs or buttons as I call them) and stick your tongue on it to see if it gives a charge.. if its good, it will give a charge. Same concept, only take a volt meter and hook it up to a battery that isn't connected to anything, it should give you some kind of reading.

Doing it this way though, you will be able to shut the vehicle off and you will lose your ac. Thats the drawback, but it'll be worth it when you get to go home and only of used half a tank of gas instead of a full tank :)

Really depends on the equipment he wants to power. If he decides to go with aux batteries, They cannot be stardard starting batteries. They are not designed to be deep-cycled and their life will be quite short. Deep cycle batteries would be the proper battery for this application.

Personally i would go with a VRLA or AGM battery. That way if it tips you wont have acid all over. Like i said depending on the accessories he wants to run, a NI-MH or LI-ION battery would be alot lighter and last a lot longer for the same amount of weight. Lead acid batteries have their strengths but a heavy as heck.

More info would be great!

OMG I hope you all are making 6+ figured to be driving those miles. 20 or so kills me!!!

yeah same here, ha ha ha ha but if hes a construction worker, his pockets definitely aren't empty.