Atrocious Gas Mileage Woes

[Dedaw]

Idling is where your mpg is going. And to be honest, idling really doesn't help your engine warm up. Use the block heater if you've got one, but unless cold is below 0F, I wouldn't bother warming it up before driving, just got easy until you're up to temperature. If it's -20F or lower I might start the engine before I get in and let it run while I go and unplug, scrape windows, brush snow off &c but I don't usually let it idle unless I forgot to plug it in (or I'm parking briefly somewhere I can't plug in) and the temperature is well below 0F.

I know there are mountains, but coming from the Canadian Prairies and having lived for a few years on the Wet Coast, I have trouble believing that it actually gets cold in WA...

You missed the part where I said I let it idle at work on my lunch break to stay warm.

And I've read from a couple different places that it's good to let your vehicle idle for a while until I gets warm so there is proper lubrication.

[gogmorgo]

Well, I don't know what your work entails (whether or not you're driving around), or how long it sits not running between when you get to/leave work and your lunch brake, but if it's cold enough to merit warming it up at at lunch, it's probably cold again anyway when you get back to it. My thinking is that's two cold, poorly lubricated starts, vs one colder but equally poorly lubricated start.

 

But yes, conventional wisdom round these parts is that fuel economy sucks in winter because vehicles need left idling to warm up. And that's the point I was trying to make, that the idling gets you.

On the other hand, my dad doesn't leave cars sitting idling, his mpg's don't take much of a hit at all, and he's clocked 250k miles on his ex-rental Chevy 3.4. Beyond changing fluids on a somewhat regular schedule, the engine has had no maintenance whatsoever. I don't know if it's even had the sparkplugs out. And it's never been left idling to warm it up for more than a couple minutes, even at -40. There was a study done here at the U of S a while ago, and while the engineers doing the research where hesitant to draw conclusions, their results mostly suggested that it doesn't do much good to idle to warm up.

[Biotex]

I agree not to let them idle too much. They tend to run rich because the converter temp never gets hot enough. The prolonged running rich is not the best for engine cleanliness which will reduce mpg's in the long run.

[Comanche County]

As mentioned above...have your clutch checked out. Ensure its bled properly, if its not disengaging all the way it will make it difficult to shift, especially into reverse. As stated above, I too usually shift into another forward gear before going to reverse. Don't ram it in gear. Give it a little rev, plop it in a forward gear, let out on the clutch just slightly to move the truck just a bit, then slide it in reverse and go.

 

However, your pressure plate may be going out and not completely disengaging. So it could be new clutch time. Bleed it first, if its still tight to shift, then you probably need a clutch kit.

 

You don't need to let it idle for more than just a few minutes. It should continue to warm up in a mile or two down the road. If the engine isn't warming up enough to blow hot air out of the heater, then cut a small piece of cardboard and slide it in front of the radiator. Don't cover all of it or you'll overheat. You'll have to experiment a couple of times for the right size depending on your truck's cooling efficiency vs the ambient temperature.

[Dedaw]

Sorry for the late response. Once I'm done helping my buddy toss in his tranny ( :wall: ) I will be bleeding my clutch and pumping some new gear oil and lucas additive into it as well to see if that helps at all. As far as the idling, it was not to warm up the truck, but to warm up myself (sitting in the break room isn't much warmer than the sub-freezing temps outside). However, once my buddy's truck is running, he will be driving so it doesn't really matter. Besides the times at work, I only let it warm up for about 5 minutes while I gather my things and head out the door and de-ice. :thumbsup:

[gogmorgo]

Guess I can see that. Still, my experience is that until there's heat in the engine, there won't be any heat coming out of the vents, and it does take a while to warm up when idling. But whatever buoys your float.

[vaquaro]

A better solution to staying warm at work ......Buy a re-chargable battery heated vest , I have one and it works amazingly well . 3 heat settings , warms up quickly then lower the setting , it will last about 10 hours . The distributor is in Calgary . It will cost you about $200 :thumbsup: