Okay guys, another fuel economy question for you regarding a couple engines.
If you had your choice, which engine would be a better candidate for a fuel-efficient build, a 352 or 351 Windsor?
Given the current situation around us now has me thinking more about MPG than HP.
Would still like to have good torque and a throttle responsive engine, only focus more on efficiency.
Factory cylinder heads, pump gas, backed by a C6 in a 4000lb truck. Will be using an aftermarket throttle body EFI system.
I do have one of those overdrive Top Loaders that came in late '70s trucks I could install, if it would be worth the trouble.
As always, any input greatly appreciated.
My best MPG FE is a current truck (F100 Ranger '66) with a stock 352 and a factory Overdrive and 3.25 gearing. Consistent 22 mpg @ 65 MPH
where as a typical 352 with a 3.50 gear or a F250 with 4.10 & taller tire is 10-12 mpg. Factory 2v carb always the best. Tried other 2v's and lost 3 mpg.
Another daily 352 truck that has a added 1961 4v intake and holley and fine tuned with as much timing as I can give it is 14.5 mpg if I drive it nice but now the holley is giving issues so mpg recently dropped under 10.
I have found as typical the manual trans always seems to give better mpg.
For fun of it I wanted to see what I could get out of a 390 with low rpm power and MPG main goals. Started off with a .020 390 block and custom pistons with better ring pack, 9.00 comp, idle to 4000 rpm custom cam and will be running a c-6 with a GV OD and a 3.50 gear set to start off with. I have a few extra 3 spd overdrive (factory type) transmissions I may try. Goal is 18 mpg @ 65 mph. For this one I had Drew do me up a 390 GT Holley and I added 406 manifolds from Kugal. Excited to see where it's at for power and mpg but thinking may not quite get to 300 hp but should make incredible tq.
Truck I drive the most I did a 2020 Raptor Crate engine and a 10spd auto with a 3.50 gear but switching to a 3.0. It gets 25 mpg @ 65 on 91 and 20 mpg on E50 while making over 600 hp to tire and 658 tq to tire. If I get too happy with throttle it drops to 17.
The factory 3 spd manual OD trans are a great deal for mpg. I have found the GV OD is also a great improvement.
Did one 351w and was not impressed with mpg or power.
Sound funny to say FE and MPG in same sentence but the stock 352 with a tall gear and od shocked me as to what was avail from factory 56 yrs ago.
Good information, thank you.
That first 352 is indeed impressive. On the second 352 truck, what transmission and rear gear were you running?
On the 351 Windsor, you're not the first person I've heard who says it doesn't get good mileage. They come with some pretty poor cylinder heads designed for the 302, and they are even stifling for that engine.
I wonder if it's a case that the heads just don't flow and consequently, you need to lay into the throttle more to get it to do what you want. Or maybe most of them found their way into F-250s and were just overwhelmed with tonnage?
Since the deal with the Explorer didn't materialize, you have me taking a look at the 352 again.
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