Need gas MPG help with '00 Silverado 5300!

I doubt a K+N or similar filter will do anything at all,except maybe get you fewer MPE.(Miles Per Engine) If it was that easy to get better mileage the engineers would surely use them on new trucks. There has been considerable discussion here and on other groups about these filters and while a few use them and seem to like them,my personal opinion based on the available info and my own observations is that they may have some limited benefit on a modified engine running at full bore.But for street use on stock engines it seems doubtful that any benefit would outweigh the potential liability of increased induction of dirt,and contamination of the air sensor. As for your mileage,I don't have a 5.3 but your MPG doesn't sound too bad from what I've seen. I always warm mine up a bit before starting off in the morning so I'm not running around with the start-up enrichment system in play.Your driving style has the most effect on MPG.Then there's tire inflation,unnecessary weight etc which I guess you already know about. Best.....Brian O.

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I don't know, I've known people who've used them and seen substantial improvements.

Well its SUPPOSED to get around 19 highway, I haven't even come close to that yet.

Count your lucky stars you get that much. A friend has an 03 Avalanche and can't get more than about 14 on the highway. I thought it was his driving, but we took a road trip and 14 is the number with the cruise set at around

1. Funny though my 88 van gets similar (read:: not better) and is a 5.7 old school throttle body v8 and 17 years old with 160k I might add. Go figure.

Brian

Mike,

As far as air filters go, AC/Delco is the way to go. K&N is crap. An oiled filter is not good for your engine. If anyone tells you different ask them how many MAF sensors they've been through since using K&N. You will be better off buying a good exhaust kit (Flowmaster, Gibson, Edelbrock, etc.), but will only see a few MPG improvement. I have an '04 Sierra w/ the 5.3 and an Edelbrock 3" exhaust. I get 17 MPG in town and 20 MPG Highway. A higher gear (lower #) gear in the diff may help mileage, too.

Cheers, Kyle

Elaborate on the exhaust kit. What exactly are you referring to? Also, how do I figure out what my differential is right now?

A cat-back exhaust system.

Check the RPO codes on the sticker in your glove box. GU6=3.42 GT4=3.73 GT5=4.10

Cool, thanks alot man.

Another question, what kind of performance/fuel economy gains do you think I'd see with one of those exhaust systems?

I don't think you'll see any improvement. I have the Magnaflow Cat Back Dual system on my 99' K1500 with the 5.7 liter and I get 14.5 to 15.5 MPG on the average. I drive about 50% of the time highway and city mix. Of course I got the same before putting them on. It does run better though and that's what they advertise and what I put them on for.

Brian

The other thing to be aware of is opening up the exhaust will improve the mid to high rpm range performance, and help the fuel mileage on the highway, but often hurts low rpm performance, which can harm, fuel mileage in town.

Whitelightning

The real question should be (since you asked about mpg) is will any of these mods ever be cost effective. Don't think you can justify the cost savings against the initial outlay of cash. Course performance is a different issue.

19 mpg highway.. down hill, foot off the throttle, gust of wind pushing at the tailgate.

19 mpg highway is figured at 50 mph, level road, windows up, accessories (read AC) off. Your actual highway speed and driving habits will have a much bigger impact on your MPG than anything that you can bolt on to the engine.

My last trip I averaged just at 20 mpg. This was with the cruise set on

75-80 the whole trip. 2004 1500 CC with 5.3L, 3.73 gears, bed cover and custom programmed computer.

I have a stock 2000 2wd 5.3L Silverado 1500, and get 20 - 22 MPG. I keep my foot out of it. In a hurry, and it can drop to 14 - 15 MPG.

If it's hot, use the air conditioner. I have neveer noticed a change in MPG due to air conditioner operation.