fuel mileage with twins

[2uphill]

What have you guys experienced with mileage who have been running twins. I realize there a lot of factors but would like to hear thoughts and facts

[9312v]

Roughly 16mpg for me DD city with top speed of 60, no freeway driving. Very spirited driving mind you.

[2uphill]

trying to tell me you can do better... what spring would yoe suggest

[2uphill]

I haven"t refined my sense of humor, but I'm workong on it ...(it;s only taken me 62 years to get this far)...what issues do you have at freeway speeds...with your particular setup...I can assume/guess...but lack the knowledge of the potential of the mods not being much of a mechanic. I am determined to learn.

[PToombs]

Mileage has very little to do with twins or not. It has to do with your right foot 90% of the time. If you stomp on it from lights and hot rod, mileage is going to suck. (voice of experience;) ) Injectors and settings do make a difference, but if you drive easy you can still get good mileage with big injectors. I get 16-17ish around town, and sometimes as low as 15 if I am driving it hard. Highway I get mid 19s at about 75mph. On the way back from SOP this fall I ran almost 2 hours at 80mph, and that tank I got about 17mpg. If I cut it back to 70 or so, I can get about 20 or a little over.
I have a set of honed 5 x .012's and the fuel screw is about 2 turns from the bottom.

[2uphill]

appreciate that...I was hoping that (your answer) was the case but assuming to often gets me in trouble. 17'ish mpg is fine It"s the max power to go with it...and know with everyones help it will all b good ...THKS... (haven't figured out how to post thanks underneath)

[PToombs]

Max power? A little over 400 ponies and well over 800 ft lbs of torque at those MPG's, I think it's darn right respectable! Try getting that mileage at that hp with a gasser.

When you want to start a new line, hit "enter" and the cursor will drop a line.
I just came from your pics page, write what you want, then hit "enter" and paste your "img" tag in the line below. It keeps the pics centered and the writing above them.

[Richie O]

Fuel mileage will depend on what the twins weigh,,,,,, Pete's dream,,,,,,,,, hot plump twins,,,

[PToombs]

1 for me, 1 for Levi!

[Tacoclaw]

I got my best mileage with twins, s362/12 and S475/1.32.


Truck got around 18 with the S300, a 19.9 that I rounded up to 20 with twins, and I'm back down to 17-ish with the blower. I'm probably gonna rehook the stock actuator that held blower boost down to 3psi. Use it to unload it some at cruise.

[2uphill]

wow...thks guys ...I see/hear lot of guy's using twins, but haven't heard these specifics that are critical for me as I make choices...(though I'm sure it's elsewhere in this forum)...downside of being a new guy I guess...thanks again guys
I guess while I'm at it what about upgrades on drivetrain are a must?

also apreciate the posting tips...(I'm not real computer savy )

[PToombs]

If you have a stick, a better clutch is a must, an auto, plan on a good stout rebuild with an aftermarket converter.

I'm not real computer savvy either, I been learning as I go. That's why I pass on tips, BTDT!

[2uphill]

have the 4500...bout due for a clutch anyway...considering 19.5's as well...seem to last longer..(not much for traction though)...would it pay to put bigger input/output...intend for this truck to last ...hopefully be my last

[RCCUMMINS89]

Fuel mileage is almost entirely controlled on a few things..........1, your foot. However, your foot shouldn't (unless one can't hold a steady pedal) have any bearing on sustained highway mpg.

Sustained highway fuel economy is based on load. Timing, changes load on the engine, and completion of burn. Injector size usually has zero control, assuming things are timed right, on sustained speed fuel economy. The amount of boost, has a direct control on load that the engine sees. The higher the cruising boost, the lower the fuel economy. Assuming that is one is still getting enough air to burn the fuel needed.


Clear as mud?

[2uphill]

yeh.. ...just a minute...looking for my goggles