318 MAX fuel economy builds?

@Dmopower I have found that the ratio’s in the “2’s” will get the 20+MPG. The 3.23’s even with large tires get close but I haven’t seen a cigar from them yet. Probably so with and OD!
I’m waiting on autopar3000’s reply as I’d like to know as well. Though I’m sure it’s answered in the Magnum swap section. I have an older Hyd A-500 for use later.

The OEM FI is hard to beat on many fronts. But I think it looses against a carb in that the intake charge is cooler with the fuel running down the runners and as long as it is well atomized and running lean, you’ll get the mileage.

The straight, down leg and annular boost are all capable of delivering good mileage but it’s at a mostly closed throttle. @AJ/FormS was saying earlier, barely having the throttle cracked open is where cruise needs to happen for the carb which is crazy hard if the car needs rpm to stay at speed.

The annular booster has a nice response when the throttle is opened up as much to activate it. This is much more throttle opening than you want and anytime. At least in a mileage search.

I’ve run the straight and annular boosters. I don’t remember if I had a down leg Holley. The Carters are so far down the crab throat though not in the barrel itself, it’s like a catch 22 if it’s a down leg or not. LMAO

Autopar3000, I tried a MSD on my Dakota for an edge in mileage. That’s all it delivered. If the best you have gotten is 19.6, I hesitate to suggest a MSD, but it could put you over the edge. Open up the plug gap until there is an issue. I routinely used a .055 gap in my ‘03 V6 Dakota.

I did edge 20 on rare occasions. But it was not the norm. Like you, a solid 19 was the best it got on an otherwise dead stock truck. The weight was in the mid 4K.

I’d also live without the old car engine feel for a V8 OEM FI drivetrain. It’s worth it IMO.