Riflemanpro

Odd question but I would like to know. I was wondering what would get a better fuel economy, a built 460 BB pushing 600-650 horse or a built and supercharged 281 pushing the same horsepower. I would like to know because the 460 is cheaper to build but I still have to drive it.

SXGT

you have to look at things like Fuel injectors and AF ratio, type of tune for 87 or 91. anything with upgraded fuel pump and injectors is going to KILL mpg

TheDutchTexan

Probably the small displacement mill. But both will have to run premium gas, and that'll kill your wallet if you drive it a lot.

Which begs the question; Why do you even mention big block and mpg in the same sentence?!

I said to myself that if I ever get something old I'll be putting in a big block optimized to run on 87. That'll still put out 500hp/tq, but not kill every time one has to fill up.

rebus

My twin screw supercharged 281 auto with 39lb injectors, GT500 fuel pumps, @ 9psi, gets 28-29 mpg highway at 70 to 75. Short trips in town are anywhere from 13 to 16 mpg. Instant torque that feels like a big block at the push of the pedal, without the mileage penalty that the 460 would bring, as long as you drive like a sane man the majority of the time. If you are going to be into boost all the time mileage will suck, keep the vacuum up with a soft foot on the pedal and the bypass will stay open and the blower just spins with minimum drag. Like Justice said, premium here is about 20 cents a gallon more than reg so it's another factor. Just my opinion, but I'd say blown 281 hands down.

Riflemanpro

I know it is weird to have 460 and fuel economy in the same sentence, but I just wanted to know. I am building a pro street dragster that will work on the street but will also kill the strip. The AFR on the 460 will be somewhere around 9.5:1 and the 281 will have about an 8.5:1 with a 15 psi boost from a KB supercharger. the injectors on the 281 will be 60 lb/hr.

Dragonus18

Don't be afraid to ask. You never know until you ask. I have a procharged GT and I get normal fuel efficiency as long as I don't beat on it. 18/25 is what I get.

shadybiz11

I have a 281, 5 speed, procharger with intercooler, 40 lbs injectors, 91 Octane. Last tank was 15.9 MPG hot rodding through town.

Riflemanpro

can anyone estimate the milage from a 460?

Riflemanpro

thanks for the info and polite reply

Dragonus18

No problem buddy.