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Fuel milage

Discussion in 'Chevy Trucks' started by 90plow, Apr 17, 2003.

  1. 90plow

    90plow Senior Member
    Messages: 739

    My 95 gmc 1500 short bed Auto 4x4 with the 305 is getting about 12 mpg.:confused: Does that sound right? It idles for about 15 minutes every morning and in a 26 gallon tank I went 228 miles using about 20 gallons of fuel. I figured the idle would eat some fuel but not a whole lot over 15-20 minutes over a week and a half. What do you guys think?
  2. Team_Yamaha

    Team_Yamaha Senior Member
    Messages: 240

    Well, here is what I know. My cousin has a 96 Chevy 1500 ext cab. short box, 4X4 with 4" lift running 33 Kumho A/T's and a 305 with auto setup. He told me that he gets right around 11 mpg, and has gotten as bad as 8 mpg. He drive about 20 miles to work, 15 of which are highway and 5 miles (at most) being in town. And personaly we have a 94 F-150 reg cab long box, 300-6, 5 spd with 2.5" suspenion lift and 33" Kumho M/T's for our shop truck. This truck only runs in town and get about 9 mpg in the winter and 12-13 in the summer. So I would say that your mileage isn't out of line be anymeans. Hope this help, but hopefully the Chev guys can help a little more
  3. wyldman

    wyldman Member
    Messages: 3,265

    There are a lot of things that can affect mileage,but your in the ballpark of what those trucks normally get.

    On average you should be seeing 12-15 mpg,will get better on the highway and with warmer weather.The extended idling doesn't help either.
  4. Arc Burn

    Arc Burn PlowSite.com Addict
    Messages: 1,141

    Your only one year shy of the Vortec motor which did see minor fuel improvements,my 95 ext bab Z-71 ate gas like there was no tomorrow,my 99 was better untill i started playing with new tire combos.I would say for the year your pretty close to normal.
  5. ToyotaPower

    ToyotaPower Senior Member
    Messages: 129

    90plow, What comes to mine,is have you done a full tune up on your truck recently, that will help with improve mileage.
  6. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Stop letting it idle for 15 minutes every day. There you mileage problem. Fire it up,wait til you have oil pressure,drive easily until the engine is up to temp. Your mileage is normal,IMO. The 035 does no better on fuel than the 350 from my experiences,you have to use more pedal to go the same speed,makes up for any gains from the smaller engine.
  7. Chuck Smith

    Chuck Smith 2000 Club Member
    from NJ
    Messages: 2,317

    All the hills in your area sure don't help. IMO 8 - 15 is typical.

  8. tileman

    tileman Member
    Messages: 55

    I would have to agree with Chuck 8 to 15 is going to be about all you are going to get. My 2000 GMC 350 Vortec ,4spd auto, with 4:10 gears on the interstate doing speed limit 12 to 15 tops. Now I know why GM put 34 gal tanks on these trucks.

  9. Mike 97 SS

    Mike 97 SS Banned
    from U.S.A.
    Messages: 1,106

    Not to change the subject, but since we are talking about size of fuel tanks, the Ford Excursion has a 44 gallon tank, thats huge! :eek: How can you find out how big a gas tank is in a vehicle for sure? I dont mean by running it to empty then filling it up, cause that way you never get the correct amount cause there is always 2,3 or even 4 gallons left in there. I say that cause I have a customer with a newer Excursion and he knows for a fact his tank is 44 gallons, yet when he runs it down to EMPTY on the gas gauge and comes in to fill it up, the most I ever saw it take is 41-42 gallons. Im sure they make it like that so you think its really empty but meanwhile its not. Its better to have some in there still and not run out, than to have it reading a 1/4 tank and it dies out cause its empty. Is there a way of telling by the VIN what size tank you have? Maybe the owners manual? Im curious to what size tank by Chevy pick up truck has. It may have the 26 gallon tank like mentioned way above, but im not sure. Mike
  10. Got Grass?

    Got Grass? Senior Member
    Messages: 641

    Mike, open your manual up. It's right in there w/ the rest of the liquid's.

    90plow, You would be surprised at how much gas your truck eats idling. at 15-20 min a day thats over an hr. a week & a couple gallons of fuel = a few $'s down the drain.

    As far as mileage goes. we own trucks, it's never gunna compare to your womans little Saturn... 4WD will eat more gas even when not in 4WD as there are more moving parts then a 2wd.

    With my '01 2500HD I've noticed by a few miles per gallon, lowering the tailgate helps a lot especially on those highway trips. Instead of air going over the truck & hitting the gate it just keeps flowing, reducing drag. Thats why they makes those mesh nets...

    Idling eats up gas & is pretty bad for your vehicle. The fuel doesn't burn as efficiently, burns at a lower temp. & will clog up your engine & converter much quicker. just take a look at the mileage big city folk end up replacing theirs at. Emergency vehicles too, I used to always wonder why they left them running constantly eating up our tax $'s in fuel costs. Until I realized how much power their radios, lights & other junk eat up & would kill the battery in 5mins if turned off.

    When it's cold out ALWAYS let your truck warm & get those fluids flowing before you take off. Just take a look at what happens to tranny fluid in your plow when it's cold. It doesn't flow properly & ya wouldn't want to spend thousands because you woke up a little late & were in a hurry.

    In the warmer months let the oil pressure build up to normal before you take off. For those couple seconds it's building up go over the rest of the gages to make sure everything is working properly & you have enough fuel.

    To figure out your mileage properly fill your truck up completely, record your mileage. Next time you fill up, fill your tank completely.
    Figure out how many gallons you used up & divide that by how many miles your drove. Too many people just fill up run to empty & divide the miles that way but it's not accurate as who knows how much gas is really left in the tank.

    The new Chevy's have an HR meter that can be used for figuring out maintenance. I like to use it to figure out my average speed for a given trip or even the life of my truck. It's just another interesting piece of info. Take your Hr's & divide by mileage. Some of you guys will be shocked w/ the results.

    The gas gage comes on where there are a few gallons left for a reason... So you have enough time to get to a gas station.
    Say your cruising down the interstate in the middle winter in South Dakota or some baron cold place. Ya wouldn't want to pass up the last station thinking you have enough fuel to get to the next cheaper place. See the fuel light come on & know there was no way you were going to make it to the next station, especially knowing you were in the middle of no where, the closest auto club tow truck was hr's away & you would soon be stranded & freezing your ass off. That would just **** ya off now, wouldn't it?

  11. PDQ Pete

    PDQ Pete Senior Member
    Messages: 139

    I have a 95 chevy short bed ex-cab 4x4 with a 350 I get between 14-16 MPG
    Thats about 75% highway driving, Im pretty easy on the gas pedel I put A-C Rapid fire plugs in it dont know if that helped with milage I also have a flowmaster cat back system I see your 17 maybe that has something to do with your mileage
    :D Pete:drinkup:
  12. Mike 97 SS

    Mike 97 SS Banned
    from U.S.A.
    Messages: 1,106

    OK got my manual in front of me for the Chevy pick up. Gas or diesel is the same size tank on shortbed, which mine is, 26 gallons. Longbed, gas or diesel, 34 gallons. Then it says Four Door Model Standard 34 gallons. Chassis-Cab Models Standard Side Tank 22 gallons. Optional Rear Tank 30 gallons. 3500HD Models Standard Side Tank 21 gallons. Optional Rear Tank 32 gallons. So I have the 26 gallon tank. Thanks for the help Mike. :drinkup: Mike
  13. wxmn6

    wxmn6 PlowSite.com Addict
    Messages: 1,037

    Ok, I read in other threads that idling is not the best thing to do with the truck, but you have to let the truck idle during cold winter days to warm up, get the fluid warmed up & circulating.

    What part of engine or components do it hurt when idling?

    I guess this is why some trucks have high idle.
  14. John DiMartino

    John DiMartino PlowSite.com Veteran
    Messages: 2,154

    Stephan,you wont hurt a gas motor by warming it up for 15 minutes. The only thing you hurt is engine life and fuel mileage.A gas engine will idle at 1300 degrees EGT,so they warm up. Diesels should not be idled to warm up.They should be started until oil/air pressure is up,then driven under light load(under 7-10 psi boost)on a Cummins,until they are warmed up.The only excpeptions are diesels with exhaust brakes,they can be left on which will load the engine enough to fully warm it up,although it will take a long time.The PSD has a form of exhaust brake,butterfly valve to aid warm up,it works well,although not as good as a true exhaust brake.I knwo my 12V Cummins would hold 180 degrees down to zero degrees outside,once it was warmed up it would hold it.The 24V's run cooler and my 24 V will cool off even at 30 degrees,from 190 to under 150 degrees in under 15 minutes of idling.It will never warm up ,just sitting idling unless its 90 degrees out with the A/C on.
  15. Got Grass?

    Got Grass? Senior Member
    Messages: 641

    A Field Service Engineer at International, had this to say about Diesel idleing:
    "If the engine is allowed to idle for long periods there is the possiblity of fuel residue collecting on the exhaust valve at the stem. This usually happens when fuel quality is low. This residue may build up over a period of time to form a sludge which may harden into a resin over night in cold temperatures. This resin can prevent the valve from fully closing, which can lead to piston-valve contact. Also the resin may cause the valve to stick which will result in the push rod becoming bent.

    The hydraulic lifters will pump up to reduce the clearence caused by the bent push rod and this can cause the push rod to bent more. It is possible that the rod can bend enough to become dislodged from the rocker arm or lifter, which in itself may cause damage due to the rod being loose inside the engine, and the lifter may come out of its bore which would be indicated by no indicated oil pressure on the gauge.

    Due to the high compression of a diesel engine, if the exhaust valve is stuck closed this can lead to the intake push rod becoming bent and the same series of events describe for the exhaust valve above may occur. This condition where fuel residue collects on the valve stem is referred to as "wet stacking"."
  16. Got Grass?

    Got Grass? Senior Member
    Messages: 641

    After searching some more this is what I gathered.
    Obviously besides wasting gas.
    Vehicles are designed for maximum efficiency at highway speeds.
    Aerodynamics, burning of fuel along with everything else.
    Fuel is made to burn at a certain optimal temperature anything lower will produce more carbon build up. the engine is designed to remove the carbon most efficiently at higher rpm's with the improved internal air flow. Carbon likes to cling to the spark plugs & make the situation even worse by fowling up the plugs. Most of the carbon is removed when the RPM's go up but gets trapped in the cat converter causing that to clog up sooner & reducing engine performance even further.
    Along with the carbon.
    On a hot day the engine's fluids flow slower at idle, coolant, oil, A/C, etc.... That along with the heat the engine produces it's self & lack of air flow under the hood will cause everything to create excessive heat.
    Driving with a cold engine will create it's own problems with the lack of fluid flow & pressure, that along with a sudden build up of heat can create havoc on the system.

    So simply let your truck warm up to the proper temp & drive.
    It's not really as bad as I seem to have just made it look.
    There are much more important things to worry about then letting your truck idle for a while, But if you plan on keeping your truck forever & want the best MPG possible it's something to think about

    Last edited: Apr 19, 2003
  17. johngus

    johngus Senior Member
    Messages: 117

    I think most owners manuals don;t call for warmup periods.I would just wait till You have oil pressure,fast idle to come down and then drive easily for the first few miles.Isn't that the biggest benefit of fuel injection?You no longer need to deal with choke's,which work great when setup properly,will drive you mad when not working right!save gas don't warm up for more then a few minutes max.
  18. 90plow

    90plow Senior Member
    Messages: 739

    I'm going to replace plugs wires and cap. This will help also. I only let it warm up because the whole truck would be a block of ice at times or it was just really cold up to last week i was letting it sit while I was getting ready for school. I didnt let it warm up at all so far from last week and ive gotten over 100 miles on a quarter tank. The way I drive sometimes :rolleyes: well you were all 17 once :angel: