Impressed with my truck's mileage.

[slimneverdies]

Originally Posted by Clyde65

If it were me, I would take a week vacation, call a buddy ( mechanical one) and dive knee deep into that 5.3 swap! if you have your motor, your trans, your harness ( custom) and your PCM, you wont need much more, oh and an 87 FI tank. you should be easily done in a week. youll be glad you did!

I think this is why I haven't move forward yet..... I only have the engine and trans. All the wiring and computer stuff is what's making me second guess this. Then there's getting the dashboard to work.
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[gchemist]

I just averaged actually recoreded 15000+ miles on my ZZ4. I've documented the miles since breaking in the ZZ4 on a 1000 mile trip. Average total with city, highway and lead foot = 16.5 MPG. Lowest at 11 MPG, yea really lead foot. Highest 25 MPG, wow great back wind lower speed! Average now is 13.5-15 if I keep my foot out of in the city. 18.5 MPG on straight highway speeds of 70 MPH. Not bad for a square body. The difference is torque. The sweet spot for a 305 is ~2000-2200 RPMs at highway speeds. Keep it there and you'll do great. Keep city RPMs below 2300.

[NCD1966]

I've gotten 15 mpg city with my bone stock "84 sliverado. 305 engine with th350 lockup convertor and 3.08 gears. I guess I'll find out what it gets on highway during cruising the coast

[blackbeaSSt]

is my q-jet the reason im getting 9-10? or is there anything else i need to be looking for?

[NCD1966]

hey you guys with bad fuel mileage with a q-jet and a 305.

my 84 had the same problem for a while getting bad gas mileage. It ended up being the vacuum lines were dry rotted and they just disappeared. The truck still ran great but just got bad fuel mileage. We ended up replaceing a few lines and pluged the rest.
It solved the bad fuel mileage problem.

Just an idea, you guys may have the same problem.

[Goldfinger]

I dumped the q-jet on my 305/700r4 for an edelbrock and now im getting low to mid 20's. I have changed my driving style alot. Easy swap except the egr gets in the way. you just have to take the spacer and fill it with jb weld bake at 400 then install with gasket sealent.

[blackbeaSSt]

ncd and gold, thanks for the advice. i'll have my mechanic check it out tomorrow when he has the truck anyway!

[68longhorn]

I still run the Q jet and get good mileage

[Goldfinger]

Well mine had seen better days and after 25 years and 4 rebuilds it was toast.

[chevymotocross]

YouTube - PIC_0060

Nice video and explanation of this guy's hydrogen setup on his 87' GMC. Never heard of this conversion, don't know how much it costs, but I will definitely be researching. His initial mileage numbers before the hydrogen install are low, so I'm not sure if he has a 700r4, and what gears, but his new mileage numbers are impressive for highway.

Anyone have any info on this system? Seems like with that much water coming out of the exhaust pipes, I might need to invest in stainless. Also, not sure if turbo style mufflers with packing would be ruined with that much water.

[James McClure]

Just watched the video and shot it full of holes. First off, he started it cold, there will always be water on cold start. Any combustion process has some water as a byproduct. Next he is using a simple process whereby you break water down into oxygen and hydrogen by electrolosis. The amount of hydrogen & oxygen produced is small and the speed of production is very slow. You would need 50,000 or 60,000 cubic feet a minute to make any difference. A cubic foot of gas is 288 cubic inches. 1 revolution of the eng is 350 cubic inches. With that info in hand, at an idle of 650RPM you would be processing 187,200 cubic feet of a gas for every minute of operation. Think about it for a minute. In this day and age when the car companies are looking for every advantage to boost fuel economy and in turn sales, don't you think they would be all over this like white on rice? Hydrogen production is expensive because it uses lots of electricity. In a vehicle, where does that come from? The alternator. What runs that, the engine. Which in turn gets it's energy from it's fuel. What the writer in the article is suggesting is a perpetual motion machine which defies all the laws of physics. Don't waste your money. Tune the eng, go thru the carb and lean it out, drive with a soft right foot. jim