I'll be a fun project for some

[SilveradoMike]

On redusing brake usage. Anyone ever tried hooking up a tazer to the brake switch so when you press the brake you get a "reminder"? lol. It's an idea.

On starters. Yes Ive actually had one on my last ls series vehicle (03 express van) and they do last longer but my experience was that the gears start to wear and make awful noises after a while. I do forget what brand mine was but it was about $220. IMHO its all the same regular startes wear motors gear reduction units wear gears. All that torque has to go some where its just what breaks first.

[War_Wagon]

Does your truck have aluminum driveshafts? I can't remember what year they became standard.

[wmjinman]

LOL - tazer hooked to the brake pedal!! Love it!! Seriously though, dunno how hard or easy it would be, but if you could install a red bulb somewhere in front of you, in your normal field of view, wired into your brake lights. That way, whenever you step on the brakes, you'll see a big red "warning light". For fun, you could even label it "Wasting Gas" or something. One person on here has in his signature, "The brake is not my friend - the brake is not my friend - the brake is not my friend -" Personally, I really like that one!!!

Your grille block plans sound good. One on each side with an open center section should work well. Then monitor your temperature & see how it does. If it gets hot, you can trim them down, but if it stays as cool as ever (and it just might), you could consider using larger ones, or maybe installing a center one with the louvers you're thinking about. What I would think might be "trick" is to have it arranged so you can have more complete block for cooler weather, but with a removable section for when it starts climbing towards those 90's and 100 degree days. Several ways to do it - duct tape over slots or holes that can be ripped off would be the "redneck" way to do it. Or to make it a bit more elegant, you could have a removable section held on with Velcro like MetroMPG does on his BlackFly - maybe the louvered center section.

Good to see you're using your ScanGauge. . . those things really show a lot of information. I also didn't find the "Lod" function to be that useful, either. Does your 27 mph average speed include all your stops, or is it only during the time you're moving? Wow, I really hate to think about all the idling you're doing. That's gotta be killing your average. But then, I "get it" regarding wanting to save your starter. Guess that's just the price you pay for being a delivery man, eh? But like someone already mentioned, I'd be really surprised if you could get 25 mpg in that thing without turning the engine off more. . . "idling = zero mpg".

[SilveradoMike]

The 27mph includes all stops. What do you think Id see a bigger improvment from e fans or grill block? Hill climbs are killing my average right now, still trying to figure out the best method for climbing.

[darcane]

I used to daily drive an '03 Silverado with a 4.8. Check out my thread in my signature. If it had a manual like yours, I'd probably still be driving it but manuals are damn near impossible to find behind a 4.8L.

Grill block is very simple, I would start there.

The Tahoe has the same nose as your truck and later got a nice, low air dam (my wife's '05 Tahoe has it). You could try finding one in a junkyard and bolt it on for a nice factory look.

Do you have steel wheels or aluminum?

Good luck!

[wmjinman]

I tend to agree with darcane; a grille block can be done dirt cheap in less than half an hour with an old cardboard box, a pocket knife, and a roll of duct tape, and can possibly get you up to 2 miles per gallon right then & there. Disclaimer: I have not tried changing to an electric fan (for increased mileage), so I really have no firsthand experience how much they help. Doing both that and a grille block would probably be a winner, though.

The air dam he mentions is a good idea, too. Chances are, whatever factory version is on there doesn't extend down as far as your lowest hanging "stuff", whether it be the axles, shock mounts, transmission/transfer case, or whatever. You don't want the air dam to hang down farther than that, because you'd be needlessly increasing your frontal area, but taking it down to the same level is good.

I'm afraid efficiently climbing hills is a mystery to me, too. In the little testing I did, the speed most efficient on level ground (40 mph) was also the best for going up the one particular hill I was testing on. However, this was my Jimmy with an automatic transmission, and when trying to feed it enough throttle to get to it's best BSFC load, it would always downshift, and the mileage would be horrible. With a manual, where you can prevent this, they say going up the hill in the highest gear possible, while keeping the engine RPM and load within the best BSFC range is optimum. As I recall, this is usually around 70% to 80% throttle.

[SilveradoMike]

The truck currentley has steel wheels. I am looking for a set of alloys for when I do my tires. Thanks fir the heads up on the factory air dam, Ive never seen one. And I will try some differebt hill climbing methods. I updated my fuel log for yesterday. My cargo weight killed me, just under 1500lbs. And got to my 2nd fillup with the scan gauge it was off 11.4%.

[wmjinman]

By "factory air dam", I really meant whatever is on there now that the on-coming air hits, bumper, bumper cover, or whatever. The point was, if it extends down to the same height as the lowest hanging stuff behind it, that's good. But if not (which it probably doesn't), then you should be able to improve things by making something that does & attaching it to the bottom of your existing bumper/air dam/whatever.

Maybe do a mock-up with cardboard & duct tape, then do an "A-B-A" test, and if it shows an improvement, make something nicer. Some guys use plastic landscape lawn edging, others use conveyor belt material.... Having the lower part somewhat flexible is good to reduce damage to it... Making it curve around on the sides to deflect the air smoothly around the front tires is huge, too. If you look at any of the newer cars, they ALL have that feature now.

As far as lugging all that weight you have to haul up hills, the best thing I can think of is to find your most efficient way to climb the grades & then let the speed bleed off as you approach the top. If traffic behind you allows, maybe let it slow WAY down as you crest the top, then let gravity do as much of the work accelerating you back up to speed on the other side as possible. Also, maybe pick up some extra speed before the hill so the stored momentum helps carry you part of the way up it. By practicing this technique - picking up speed by the bottom, letting it bleed off all the way up & using gravity assist to regain it again on the other side, you should see some improvement.

Obviously, if the hill is long enough, there'll still be a section where you've got to just grunt up it with power (= gas). But hitting the bottom with extra speed & then slower speed by the top could still help, maybe. ??

[darcane]

Your truck should look about like this:


This is my wife's Tahoe:


It's not the best picture, but you can see that the air dam hangs down a few inches lower than your truck does. You would probably need the air dam and the lower part of the bumper that it attaches to, but I'm not 100% sure.

The e-fans are supposed to be good for a .5-1mpg improvement on these trucks. My wife's Tahoe has the same 4.8L/auto drivetrain that my Silverado has, but the Tahoe will get 25hwy with her driving it. At best, I can get about 23 in mine, and that's using some hypermiling techniques, it would be more like 20-21 driving the way she does. Her's has the air dam, e-fans, and slightly higher gears, plus it's been lowered about two inches.

I switched from steel wheels to these aluminum wheels:

And saw a slight increase in economy. Just watch what tires are on them, when I switched to (heavier) LT tires it came back down some.

[SilveradoMike]

Yes my truck looks like the pic you posted but single cab long bed. It has the factory lower bumper valence but no "air dam" the piece thats there is still a good 5"-6" from covering everything underneath. I did just find a set of the same factory alloys you have and Ill be picking them up this weekend along with new tires. ( should be a huge reduction in rotating mass) Im going to try a partial grill block at some point this week or weekend also. I kind of worry about an air dam as I do "tap" the lower edge of the valence on things as it is now.Maybe a flip up type would work best, but thats going to take some fab time.

On hill climbing. Should I be staying in high gear or down shifting to compensate? Ie 55 mph on flat ground is about 1800rpm in 5th gear at ~15% throttle input. On a hill of decent grade or distance maintaining same throttle input speed falls off and rpm to below 1000rpm pretty quick. Should I down shift or add more throttle? Im slightly confused on this.