what gas consumption reading per engine could be logical?
 

15 gal/hour per engine for example at 5000 rpm... does that make sense to you?

That is what my floscan tells me but I feel it must be more than that...

Any idea on that?

Which engine and h.p.?
Type boat?

check the other thread.

454-485 hp in F35-7 1989

A good rule of thumb is 10% of Hp @ Wot = GPH.

From past experience I would say it is burning 46-54 gph.
The above would be correct if near max rpm.
My 502/465s burned right at 47 gph wide open throttle.
They were carb motors..efi should be a tad more effecient.

46-54 per engine or for both?

true, but most often under that real world. I've seen it and verified it more than once.

my 350 HP 454 mags would burn ~ 28 GPH WOT (accurately calibrated (<2%) Floscan)

no, that's why I told you in the other thread YOU'RE READING 1/2!

your real GPH is about 30 GPH WOT on those 385's

been there done this! I just can't tell you off the top of my head after a few years and on my 5th 12 hour night shift which switch to change!

call tech! they are fantastic and will give you the answer!

If you are making 450 HP at 5000 RPM. My math says at .5 lbs of gas per HP you will use 225 lbs divided by approx 7 lbs per gallon = 32 gal per hr per engine. The FloScan should be reading in range of 29-35 gal per hour per engine

A rule of thumb: 10-12 hp per gallon per hour. At peak torque,
you'll see the higer number. Open throttle, you'll see the lower
number.

Therefore, at WOT, on 485 HP engines, you should be
burning about 48.5 (say, 50) gallons per hour per engine.

With all these numbers I'm reading here, I can see why the diesel is becoming a more popular option! You can run a pair of similar hp diesels for the same fuel burn as one comparable big block. (not the same pleasurable exhaust note however!)
Makes a guy really appreciate the 'ole Cessna 182- 14gph at 140mph........

A fairly accurate formula if the engine is running efficiently is HP divided by 11 for carbed engines and HP divided by 12 for EFI.

At 485hp, it would be around 44gph at WOT carbed and 40.5 gph EFI.

I prolly have the numbers in one of my old books from college, but does anyone have the HP / GPH comparison for a turbine or a diesel??

I've got the Mercury smartcraft on the family's sea ray with a 6.2. It gets around 35gph at 5000rpm.

I spoke with floscan today. I have the right sensor (yellow cap model 231) but there is a red button under the gauge. this button can be settled from 1 to 4. I was on 1, needed to be on 4. So I switched it! and resetted the totaliser. Great support from them since I sent them an e-mail last night and they called me today! thanks to them!

They told me roughly what Griff said: generally speaking on a carb engine, fuel consumption at WOT will be 10% of max HP. So in my case, 485 at 10% is in fact 48.5 gal / hour per engine!

So, with my budget, I'll be good for...let's say.. 1 hour!
Or!
Much more if I go slower!:Whatever:

All this talk of WOT fuel consumption...how many of us run WOT for 5mins let alone an hour or more?

What's fuel burn at part throttle...3k, 3.5k, 4k...? I know it's dependent on engine load, etc. Just looking for ballpark numbers.

Real close.

I have 1040HP per engines and this formula would give 208GPH at WOT based on two engines and I actually burn 180GPH at WOP.

At 3200 rpm I am in the 65-75 GPH rate.

GLH

that is per engine I suppose?

That explains my fuel bill for the last couple of weekends......

At cruising speed 2900-3100 rpm on a 6.2 I can get 8-10gph

Both mills

not too bad considering the HP rating and specially your quite fast cruising speed...

Yeah Mark, and look what happens :cool:
:D

Interesting thread. I have figured out my mpg when refueling and I have gotten as good as 1.6mpg ( on average it is more like 1.3mpg) with my twin 502 mpi's. That is doing a lot of running between 3000 and 3500 Rpms. If I go over 4,000 rpms the fuel economy goes down in a hurry.

I was pleasantly surprised the first time I figured it out. I was expecting closer to 1mpg.