Been shopping Formulas and have a question about fuel efficiency. Began looking at some 271 SR1 boats with either the 454 or 502 magnum, but for the same money I can get a little bit older 311. So my question is, how much more fuel would I burn in a 311 with say 454 magnum carb engines with Bravos versus a 271 with a EFI magnum engine? I like to cruise at 45-50 mph.

One 454 or 502 MPI engine vs (2) carbed 454's. The carb'ed engines should be slightly less fuel efficient based on that alone.

I've seen where people claim the 2 engines will not have to work as hard and therefore not burn as much fuel each....but that has not been my experience. A 454 running 3,500 rpms burns a certain amount of fuel regardless, having another beside it seems to burn exactly twice IMO.

your gonna burn double, regardless, and if it was slightly less it is so slight you won't know, to cruise at 50 on a 271 you will be runnning around 4200's you can buy mine but its carbed some view that as a good thing

I have looked at your boat actually in pictures you posted on previous threads and I do like it. You think it will burn double? I know it will burn more, I am just curious exactly how much. I would love the larger 311, but also want to be able to afford to run it how and where I want.

That old school 311 is a great boat....but expect it to burn about 1.1-1.3 mpg at cruise vs about 2.2-2.4 mpg in the 271. 88242LS might be able to verify my estimate from his 271????

With the added fuel burn you get ALOT more room and ALOT better riding boat.....but I agree, if you can't afford to run it what good is it!

Generally speaking, fuel burn is primarily dependent on weight. A 4,000 pound boat will deliver about 3 mpg, a 8,000 pound boat about 2 mpg, etc.

That's what I was afraid of, looks like I better stick with a single. I only boat of freshwater lakes and never overnight so the 271 should suit me fine, or even a 252 BR. I just like the quality and style of the Formulas, also looking at Checkmates and Donzis.

i wish my 6000 lb boat got 2+ mpg, 2 big blocks are burning twice what my last single engine boat was burning, i know many variables but i'm def getting less than 2 mpg more like 1-1.3

Yeah, I like to cruise all over the lake, not just sit in a cove all day, and would like to maybe do a small poker run or two each year. I have a good friend that has a 42 Fountain with trip 600s, but he literally can't afford to run it. He only brings it out on Saturdays, never Sunday, and goes straight to Party Cove, then straight back, thats not me. To sell the boat he would have to give it away with that engine package, not to mention the 600s (carbed) are mated to stock Bravos

I know you're concerned about the fuel, but what about other factors, better ride, more space, easier to manuver, with twins there's also a additional engine safety factor, I wouldn't look at just the fuel costs, look at everything then make a decision before you go shopping.