I filled it up again and got just over 15 miles per gallon. Oh well....not bad, I guess - considering it is shod with 265/70R17 rubber.


At least I also have a four-cylinder car that I can drive to work. LOL! Unfortunately, it appears as though fuel prices are going upward once again. Unleaded regular here went from $2.45 to $2.55 overnight!!




2004 Silverado 1500 LS

 

Welcome to the site, sorry about the 4 letter F word!LOL!!! J/K

I just checked my 07 5.3 2X4 for milage and was able to get 18.5 mpg after installing a soft tonneau cover, it made a surprising difference. The newer trucks aren't quite as good as the older ones for mpg from what my buddies have told me. Your plugs should be removed cleaned and reinstalled with anti seize at least every 2 years IMO. 5W30 should be fine the 30 is the number that will concern you being in a warmer climate.

 

!. That is an optimal mileage for your setup if you don't find an aerodynamic/ fuel efficient cover for your bed.
2. The manufacturer advises using 5W30
3. Changing the tranny filter will probably increase your MPG a little, especially if it hasn't been done yet.
4. Delco Iridium spark plugs work best, but I wouldn't trust them over 50K miles.
5. I've also been lucky with the Dexcool, but this is a loaded topic here. Many people have been unhappy with it, and I certainly can't argue with them, so this one's your call.
6.It's up to you, I don't personally trust gear oil after a couple years and change it whenever I feel doubt. The RPO code you're looking for is either G80, explained earlier, or GT4-(373ratio), GT5-(410ratio),GU5-(323ratio), or GU6-(342ratio)
7. All the normal lube points are there, but I've found a mixed bag as far as what zirks are usable or even in place. You may have to install a couple of your own.
8. A thread search will probably help you here, I see a lot of people like Flowmaster,although I haven't had the distinct pleasure of having to replace my exhaust yet personally.

 

Thanks for the comments, Taz. Yeah, I have owned one F**d truck - a 1985 Ranger long bed, and one F**d van - an Econoline. Both were okay vehicles in the grand scheme of things. I have also had four different Mustang GT coupes (owned an '88, a '93, a '95 and leased a 2008 that I just turned back in). I'm no stranger to the Blue Oval; but I have had several GM vehicles in our family as well.

I'll have to check into a tonneau cover to get better mileage - or maybe drive around with me tailgate down. LOL! Those big tires are not helping my fuel economy; that's for sure.

As for the plugs, I figure it might be better to replace all of them - rather than removing & replacing them. They're probably good for 100k, so I have some time yet. 5w30 oil is fine here in VA, especially since I use Mobil-1, Castrol Syntec or some other brand of synthetic. I have used both 5w30 and 10w30 in several vehicles and have never had any trouble - especially since I change my oil rather frequently compared to most folks.

 

15 mpg optimal. Wow! I sure am glad I have an old Sentra that I can use for commuting to work (even though it is not as nice as the truck), as it gets twice as many miles from a gallon of unleaded. Some say that using premium fuel gives better mpg, but I am leery of such claims - and the extra 30 cents a gallon at the pump would surely outweigh another 2 or 3 miles per gallon.




Yep; it is even printed on the oil cap. Since I use synthetic oil and change it more often than most people, either 5w30 or 10w30 should suit me just fine.


Where is this filter, inside the transmission pan? Wouldn't they have replaced it whenever (or if) the fluid was changed? I figured on having it flushed out....but will be sure to check out the filter & its location.



I'll get them replaced with OEM or better - no doubt about that. Just a matter of when or where it will be done. Heck, I would consider doing it myself - but I don't know if the plugs are down "inside" the engine or how accessible they might be on this truck.


My gut tells me to stick with the OEM/Dexcool stuff - so that's what I will likely end up doing.....but I'll still change it out every other year. I've done that for eons with every car/truck I have owned, and it seems to have worked for me over the long run.


So the gear oil may be different for different axles? How can I tell which one mine is? From looking at a 'build sheet' I found in the glove box, it seems as though I might have a 3.73:1 ratio; but I'll double check before I take it anywhere to have it changed. Wouldn't it be like 85w90 or something thick like that?


I have a grease gun & one cartridge at my house. Whenever I get around to changing the oil & filter and am already under there, perhaps I'll be able to find all of the zerks.


From what I can see, the OEM exhaust system looks pretty decent, so a nice dual system is going to be on the back burner for awhile. I have heard that Flowmaster makes a good system, and so does Borla. I know the 5.3L is big enough to put out a rumble!

Finally, I should probably replace the serpentine belt soon; just for peace of mind - even though it appears to be in good working order (no cracks, etc.) and it might have some life remaining.


** THANK YOU!! **