Fuel Efficient '72 Chevy K20

[RaptorSentry]

Looking to get the best gas mileage out of my '72 Chevy K20, it is pretty much stock. The original engine has just recently been rebuilt. This is what I am thinking of doing, if money was no object:

1. Banks Twin Turbo (if it fits, currently they show only '80+, but then say any 350 SB, confusing)
2. Edelbrock E-Street EFI w/ Sump Pump
3. Gear Vendor Under/OverDrive
4. Custom Dual Exhaust 3" Mandrel bent 304 Stainless Steel w/ H-Pipe & Magnaflow Mufflers
5. Replace the old all-terrain tires with some low resistance highway tires
6. Add a tonneau cover to the bed.

Is there anything else I am missing? Is there anything else I can do to improve my fuel economy, other than removing the lead from my foot?

[WIDESIDE72]

"Fuel efficient K20"! thats good one! :Lol: oh you are serious. Lower it and convert it to 2wd 1/2 ton swap in a 4.8l LS and 4l60e

[Eddie H.]

If money is no object, just drive it and don't worry about it.

[brad_man_72]

Originally Posted by Eddie H.

If money is no object, just drive it and don't worry about it.

Or buy a prius, that's a pretty expensive way to save a few bucks at the pump.

If saving money is the objective, a good tune up for when you have to drive the truck and a $1000 beater for when you don't have to drive the truck.

After my ls swap and beater I get about 25mpg combined.

An added benifit when somebody hits your beater you don't care, good way to make $20 here and there. My miata gets hit so often we call it the pinata.

[WIDESIDE72]

Originally Posted by brad_man_72

After my ls swap and beater I get about 25mpg combined.

Sorry, dont know how else to say this. Hope it doesnt hurt your feelings.

[Tx Firefighter]

Originally Posted by WIDESIDE72

Sorry, dont know how else to say this. Hope it doesnt hurt your feelings.

I don't know I'd doubt him too much. Combine an LS swapped truck and a Miata and you could get a combined average of that pretty easy.

Between my little Honda DD car and my big block 456 geared dually, I still get a good combined average overall. I just make sure and drive the Honda unless I really need a truck.

[WIDESIDE72]

Originally Posted by special-K

I get 12.5 from my '72 K2500 350/TH350 with 235/75s or 12.50/33s. That is very efficient when you look at all the technology since '72 that has yielded little to no improvement. I've driven these trucks since the first energy crisis in '73 when gas jumped up from $.33 a gallon. I've just gotten used to it along the way,I guess.
The best fuel savings will certainly be found in your right foot,and that's a fact! My efficient fuel injected diesel with O/D gets 2-3 mpg better when I drive 65 in the right lane than going 75. I still have plenty of time to do what I have to do when I get there. That alone gives 60-90 more miles to a tank...a free round trip to work every 6th day.
I've never had a turbo save fuel. The 6.5TD GMs don't get near the mileage of a 6.2 NA and that's with a more aerodynamic body. I don't see much sense in all the zillions of 4wds out there with all season tires that will leave them stuck where a 2wd with good tread can go.

Originally Posted by Tx Firefighter

I don't know I'd doubt him too much. Combine an LS swapped truck and a Miata and you could get a combined average of that pretty easy.

Between my little Honda DD car and my big block 456 geared dually, I still get a good combined average overall. I just make sure and drive the Honda unless I really need a truck.

I took "combined" to mean city/ highway. Maybe i misunderstood.

[brad_man_72]

Originally Posted by WIDESIDE72

Sorry, dont know how else to say this. Hope it doesnt hurt your feelings.

You're free to believe whatever you like, no feelings hurt, 17mpg with truck pulling the boat down the highway 70mph, 18mpg with truck empty (playing a bit), 28mpg driving the miata like a rented mule most of the time.

The cheapest way to buy less gas and own a classic truck is to buy a beater, I needed a beater that id actually drive (5 speed, rwd, posi, convertible).

[coueshunter]

There is no way you will ever drive that truck enough to offset the costs your spending versus saving. The return would probably be at 200,000 miles

[WIDESIDE72]

In all seriousness, if the truck has huge oversize tall and wide tires your mileage will suffer compared to running stock size tires.

[WIDESIDE72]

I have an 09 HHR SS which has a 2.0L turbo 4 cyl. It has an auto trans as a concession to my wife. The driver info display normally indicates around 27 mpg average with mostly highway driving. I admittedly have a lead foot. I borrowed my dads 2500hd duramax once and switched cars with him. I left it with a full tank if gas. I reset the calculator knowing it would get better mileage with him driving it and it was all highway. When i got it back i had to refill it. The DID on the SS indicated 32mpg (!)

[special-K]

I get 12.5 from my '72 K2500 350/TH350 with 235/75s or 12.50/33s. That is very efficient when you look at all the technology since '72 that has yielded little to no improvement. I've driven these trucks since the first energy crisis in '73 when gas jumped up from $.33 a gallon. I've just gotten used to it along the way,I guess.
The best fuel savings will certainly be found in your right foot,and that's a fact! My efficient fuel injected diesel with O/D gets 2-3 mpg better when I drive 65 in the right lane than going 75. I still have plenty of time to do what I have to do when I get there. That alone gives 60-90 more miles to a tank...a free round trip to work every 6th day.
I've never had a turbo save fuel. The 6.5TD GMs don't get near the mileage of a 6.2 NA and that's with a more aerodynamic body. I don't see much sense in all the zillions of 4wds out there with all season tires that will leave them stuck where a 2wd with good tread can go.

[WIDESIDE72]

Originally Posted by special-K

I get 12.5 from my '72 K2500 350/TH350 with 235/75s or 12.50/33s. That is very efficient when you look at all the technology since '72 that has yielded little to no improvement. I've driven these trucks since the first energy crisis in '73 when gas jumped up from $.33 a gallon. I've just gotten used to it along the way,I guess.
The best fuel savings will certainly be found in your right foot,and that's a fact! My efficient fuel injected diesel with O/D gets 2-3 mpg better when I drive 65 in the right lane than going 75. I still have plenty of time to do what I have to do when I get there. That alone gives 60-90 more miles to a tank...a free round trip to work every 6th day.
I've never had a turbo save fuel. The 6.5TD GMs don't get near the mileage of a 6.2 NA and that's with a more aerodynamic body. I don't see much sense in all the zillions of 4wds out there with all season tires that will leave them stuck where a 2wd with good tread can go.

I had an 82 Suburban with a 6.2L diesel. My dad bought it with around 40k miles. It went through three injector pumps by 150k miles. We found a shop that used a brass impeller and that pump was still on the engine at 340k (!) still running with as much power could be expected from a 6.2 and still not using any oil between changes. I used Delo oil wix filters and changed every 3k miles. I wish i had hung onto that engine! It was painted red and i learned after the fact that the first couple of years that gm used the detroit engine (red) they supposedly had higher nickel content in the block resulting in low cylinder wear. (?)

[Auctioneerhere]

Just an FYI many of the GM fuel mileage deals are wrong. Do the math when you fill up.

[Bigdav160]

Is there anything else I am missing? Is there anything else I can do to improve my fuel economy,

Forget all those things on your list.

As mentioned by special-k, a GM 6.2L diesel swap (with 700R4 transmission) would be the most fuel efficient. A 6.5L Turbo would have better performance but it's higher torque output is harder on transmissions.

I'm not sure how hard these engines would be to locate in Europe.

With a little machining, perhaps a Mercedes OM606/603 could be adapted to fit?

[RaptorSentry]

Not planning on swapping the engine, as I just had it rebuilt and it is the original. I like the idea of keeping the numbers matching. Diesel would be great especially over here in Germany, but my plan for this truck is to keep it original as possible (matching numbers), while improving drivability, fuel economy and sound control with new tecnology. This was my father and grandfather's truck, and I want to hand it over to one of my sons when I get too old to drive. Making sure I use quality parts while doing so.

[Coley]

Originally Posted by RaptorSentry

Not planning on swapping the engine, as I just had it rebuilt and it is the original. I like the idea of keeping the numbers matching. Diesel would be great especially over here in Germany, but my plan for this truck is to keep it original as possible (matching numbers), while improving drivability, fuel economy and sound control with new tecnology. This was my father and grandfather's truck, and I want to hand it over to one of my sons when I get too old to drive. Making sure I use quality parts while doing so.

...quick question: What are you guys currently paying per litre for fuel in Germany? (Both gas and diesel)
Coley

[67ChevyRedneck]

You have a pretty expensive parts list there!

The gear vender's OD will give you the quickest/best return on fuel economy, but as I'm sure you researched, they're $$$.

Fuel injection is great, but the last kits I looked at were $1,700 and didn't include the fuel pump and lines you would need.

Unless you have a really high HP motor, a 3" exhaust is way too big for a stock-ish, or even mild 350, 2 to 2-1/4" will help your motor breathe the best.

You're English and grammar are spot on, I have you ask if you're an American living other there?

Again, I know you said the motor was just rebuilt, but a GM 5.3L with 4L60 swap with everything cost's around $2-3K depending on how frugal you can be on the motor and wiring harness, I only mention it again because the parts list you have up there is pushing 6K, but I don't know if you even have GM vehicles with that combo over there?

[special-K]

I also had a K/20 with 400SBC/4spd,same gears as other truck above (4.10),and 12.50/35s that got 12.5 mpg. It seems in a big blunt heavy truck,the more bottom end torque the better the mileage. More torque from less throttle is more like it. This truck seemed to move effortlessly. It went down the road just fine with hardly any gas pedal

[WIDESIDE72]

Almost forgot my point. I could get as high as 20mpg highway in that 3/4 ton 'burb empty with 4.10 rear and 700r4 od!

[Tx Firefighter]

I don't know exactly what he meant either for sure.

[RaptorSentry]

My original game plan was to do the following:

1. Spectre Cold Air Intake (colder air better than sucking the hot air trapped at the top of the hood)
2. Edelbrock E-Street EFI w/Sump Pump (for drivability)
3. Gear Vendor Under/Overdrive (I agree with you, Jesse, I'd expect the most fuel economy coming from this. Plus it should reduce the high RPM at highway speeds making it a little bit better on my hearing.)
4. Custom Single Exit Exhaust with Corvette 2.5" RamHorn Manifolds, 3" Mandrel bent 304 Stainless Steel and Magnaflow Mufflers (all recommended over a dual 2.25-2.5 exhaust system by a speed shop back home)
5. Tires I have to get replaced anyways they are over eight years old and rotting, since the truck has been sitting eight plus years. Planning on Toyo Open Country H/T.
6. The tonneau cover should help reduce any drag, plus keep the groceries dry.

The big thing I was looking for comments on the turbos, but I did not specify that to see what else I was forgetting. The reason for the 3" dual exhaust was that is what Banks recommended when using their turbos, otherwise I would have left it as the speed shop recommended for the above configuration. From the above comments and some more research it does not look like the turbos would provide that much more MPG, vs the cost, plus the additional stress on the engine with the turbos probably not a good thing, especially if this is just going to be an occasional driver (weekends, hauling, etc.).

As far as the English thing goes, I'm glad that I was only good and not excellent, otherwise I would be mistaken for a Brit. All kidding aside, I am an American living in Germany, for a couple more years at least.

Overall Germany is not a place for big American trucks, as they are wide compared to the European trucks and roads go. However there are you do still see them, from all the Americans who brought their trucks over, and some Germans who bought them from the Americans before they leave to go back to the states. I decided to leave mine back home with my father-in-law, till I get back to the states.

[RaptorSentry]

German Fuel Prices; US Military Members Pay
95 Octane is 1.525 Euro/liter = $7.90/gallon; $3.688/gallons
98 Octane is 1.575 Euro/liter = $8.16/gallon; $3.869/gallon
Diesel is 1.389 Euro/liter = $7.22/gallon; $4.110/gallon

[Coley]

Originally Posted by RaptorSentry

German Fuel Prices; US Military Members Pay
95 Octane is 1.525 Euro/liter = $7.90/gallon; $3.688/gallons
98 Octane is 1.575 Euro/liter = $8.16/gallon; $3.869/gallon
Diesel is 1.389 Euro/liter = $7.22/gallon; $4.110/gallon

....I don't completely follow with respect to the Euro cost per litre and the 2 resulting costs per gallon.
It looks tho' based on what I understand to be European fuel costs that you guys are generally paying about $7.90/Gallon for gas?
....I'm also assuming that thiis based on the (smaller) U.S gallon and not the British gallon which is a bit bigger, correct if I'm wrong on this.
(ie: U.S gallon is about 3.8 litres while the British gallon is..4.4 litres? if memory servers correct)
....hey 95 and 98 Octance....nice gas!
All Good
Coley

[RaptorSentry]

Germans pay:
$7.90/US gallon for 95 Octane
$8.16/US gallon for 98 Octane
$7.22/US Gallon for Diesel

US Military members stationed in Germany pay:
$3.688/US gallon for 95 Octane
$3.869/US gallon for 98 Octane
$4.110/US gallon for Diesel

US Military have a Status of Forces Agreement with the Government of Germany allowing us to buy our fuel without the Germany Fuel or Sales Tax added on.

Also those are the European Octane ratings using RON measurement system, the US equivalent octane ratings are less, but I do not remember the exact US equivalent octane but it is close to mid-grade and premium octanes.