Ecoboost vs. V8 - Can you explain?

As I stated before, I got to drive two 3.5L Ecoboost F150s putting over 100k on each. My personal truck was an F150HD crew cab 4x4 with 3.73 rear gears. My work truck was a F150 super cab 4x2 with 3.15 rear gears which replaced an F150 5.0L super cab 4x2 with 3.55 gears.

My personal Ecoboost truck got better fuel mileage towing and unloaded then the 5.0L work truck I had. The work truck Ecoboost got much better fuel mileage unloaded, but about the same when towing probably due to the engine having to compensate for the very tall for a truck 3.15 gears.

However, these were two different animals when towing. I had to tow a 20ft enclosed trailer with both on a routine basis to deliver bulk parts to an oilfield customer I had back then that was about an hour and a half away. The work truck 5.0L with 3.55 was gutless down low and would down shift to 3rd or 4th at the sight of a hill when down. I have had my foot to the floor on a few occasions.

The work truck EB with 3.15's would power up slight hills in 6th, and would drop down to 5th on the steeper ones. It was very rare that it would drop to 4th, but I never had my foot to the floor unless I was passing which there was always plenty left over if needed.

My experience is that while the EB does use more fuel when towing, it is not much different than any other V8 I have driven. The one main advantage versus a V8 is when unloaded. With the amount of low end that the EB, you can do the same job(or more) with tall gears in the EB that would require shorter gears in the V8. My work truck EB with a 3.15 ratio could have easily done the same that a 5.0L with a 3.73 rear gear could have done.

srt20 wrote:
Inline maybe a better design, but they just dont fit in vehicles well anymore. Curved down hoods, shorter front ends, etc. The V block engines barely fit now. Look under the hood of a V8 diesel with turbos. Its shoved way under the cowl, and all the way to the radiator support. Then add 2 more cylinders to that length...

BTW I have a 3.5L Ecoboost. And either I have a bad one or there's alot of people that fib about their mpg. I got 7.9mpg towing a 30ft enclosed all aluminum 7.5ft wide trailer that weighed about 5000lbs loaded. And I havent seen 20mpg on the EVIC (which always reads high) in a LONG time.

Turbocharged gas engines need fuel.

GM has accomplished this fitting their inline 6 Duramax in their 1/2 ton trucks.

Area under the torque curve is what most drivers notice. The green line shows how much torque is available under about 4500rpm than any other compared engine.

"BTW I have a 3.5L Ecoboost. And either I have a bad one or there's alot of people that fib about their mpg."

Well theres that. I maintain there's 3 things most men fib about. The size of the fish they caught, the size of their ____ and the fuel mileage of their truck. The internet is the king of outlandish fuel mileage claims (and a few people who literally drive so slow and miserly that they get passed by a stiff breeze).

Inline maybe a better design, but they just dont fit in vehicles well anymore. Curved down hoods, shorter front ends, etc. The V block engines barely fit now. Look under the hood of a V8 diesel with turbos. Its shoved way under the cowl, and all the way to the radiator support. Then add 2 more cylinders to that length...

BTW I have a 3.5L Ecoboost. And either I have a bad one or there's alot of people that fib about their mpg. I got 7.9mpg towing a 30ft enclosed all aluminum 7.5ft wide trailer that weighed about 5000lbs loaded. And I havent seen 20mpg on the EVIC (which always reads high) in a LONG time.

Turbocharged gas engines need fuel.

parker.rowe wrote:


And physically was a monster. They would have been better off to design a new straight six then continue with the 300. It didn't even have a crossflow head.

Back in the early '80s I had a couple of trucks from the late '60s. Both 2-stroke diesels, same rears, same transmissions, doing the same work. The I 6 was more power full and used less fuel than the V 6. Put new bearings, rebuilt head, new pistons and liners in the V 6. Cut oil consumption, but still could not work with the I 6. IMHO, inline is a better design...

A major problem with putting a large displacement boosted gasoline engine in a truck designed for towing is that you'd never keep it cool. A 6.7 EcoBoost could easily make over 700 hp. A 700 hp towing truck would require a radiator larger than the one behind the grill of a Peterbilt.

rjstractor wrote:

JRscooby wrote:
Cost associated with re-engineering a whole new motor/supporting systems and completely re-tooling the factories? IMHO, they did that.
Had a engine that was pretty cheap to run, and real dependable back when using points and carb. Instead of putting Fuel Injection on that when needed to clean the exhaust everything had to go V. Ford put throttle body on the 302 V8, and made big improvement in power and economy. Why not the 300 inch 6? If they had, then would not take much to add the turbo

They added fuel injection to the 300 as well in 1987 and it was the standard F150 engine until 1996 when the truck was completely redesigned. Even with EFI the 300 had only 145 hp.

And physically was a monster. They would have been better off to design a new straight six then continue with the 300. It didn't even have a crossflow head.

JRscooby wrote:
Cost associated with re-engineering a whole new motor/supporting systems and completely re-tooling the factories? IMHO, they did that.
Had a engine that was pretty cheap to run, and real dependable back when using points and carb. Instead of putting Fuel Injection on that when needed to clean the exhaust everything had to go V. Ford put throttle body on the 302 V8, and made big improvement in power and economy. Why not the 300 inch 6? If they had, then would not take much to add the turbo

They added fuel injection to the 300 as well in 1987 and it was the standard F150 engine until 1996 when the truck was completely redesigned. Even with EFI the 300 had only 145 hp.

noteven wrote:


Wouldn’t they simply lose that market share because spark engines are gutless compared to diesels so buyers will look elsewhere?

Another person that hasn't kept up with modern gas engine technology.:S