Why hasn't anyone released a HD truck with a Turbo V8?

I think my 6.0 gasser pulls just fine.

What is the reason the V-10 in a HD. PICKUP has not been continued. Both ford and dodge!
I thought the Excursion with the V-10 would be the ideal tow vehicle for a bumper trailer! Guess i am wrong. We are thinking of downsizing from a MH. to a bumper trailer.

I would take an electric hybrid over a V8 turbo any day.

In all actuality, the 3.5L Ecoboost gets pretty good fuel mileage compared to engine with similar performance and capabilities. In the last PickupTruck.com half ton towing shootout, the 6-speed 3.5L Ecoboost got 11.3 mpg towing 10,100 lbs while the 8 speed Ram 5.7L Hemi got 10.7 mpg, and the Chevy Silverado 5.3L 8-speed got 11.1 mpg. The only one that beat in towing mpg was the 8 speed GMC 6.2L at 11.6 mpg although the 6.2L does require premium fuel at all times. Slap an 8 or 10 speed in the Ecoboost like the other trucks had and I bet it would have out done all of them. The only truck to beat the 6 speed 3.5L Ecoboost in loaded performance in those tests was the 8 speed GMC 6.2L as well by about .3 seconds in the 0-60 and .3 seconds in the 1/4 mile.

These results were the same in the Canadian truck King challenge as well. So saying that it uses more fuel than a V8 with similar performance and capabilities is mostly false from all of the tests that I have seen. Turbo charging is no different that today's V8s with multi-displacement systems in that they both vary the effective displacement of the engine. The only difference is that with MDS you are decreasing the actual displacement you have when power is not needed, and with turbos you are increasing your actual displacement when it is needed.


I think there are many reasons why there has not been a Ecoboost 4.0L-5.0L V8 to replace the N/A 6.2L. For one, you need an iron block to to be able to dissipate the heat of a towing duty cycle and do it reliably day in and day out. The aluminium block of the 3.5L Ecoboost is fine for the duty cycle of a half ton, and is why the 3.5L Duratec aluminum block was easily(and cheaply) used since it was already engineered. Ford currently does not have a small iron block V8 so they would have to make one from scratch. Remember, Ford took a big gamble putting the V6 Ecoboost up against the bigger towing V8s at the time so they probably didn't want to throw more money into it if they could avoid it if their gamble didn't pay off. They also probably wanted to see how well the 3.5L Ecoboost did in the half ton before they committed to building a completely new V8 block.

I also have no doubts that a small turbo charged iron block V8 is probably in the works as we speak. Why? Because CAFE standards will soon be applied to 3/4 and 1 ton trucks. Unlike what some have stated above, 3/4 and 1 ton trucks aren't apart of CAFE since they are over 8,500 lb GVWR which is why there aren't any EPA mpg numbers on their window stickers. There has been no incentive to make them more fuel efficient since most would buy diesels in the past if they wanted fuel efficiency in an HD/SD truck. Why spend the money on making a new engine if what you have is good enough versus the competition in sales and you are not getting penalized for it's dismal mpg?

Now that these trucks will be apart of the CAFE numbers in the coming years, Ford (and the other manufacturers) now has an incentive to make them more fuel efficient. Afterall, that is the reason why Ford put a 3.5L Ecoboost in the F150 in the first place and why other makes incorporated multi-displacement systems in their half ton V8s. To meet CAFE numbers.

There are probably some other reasons, but I think these are the major ones. However, I would not be surprised to see a small turbocharged V8 in the SD a few years after the new 2017 comes out.

^yes but using ford as an example, my n/a 6.2 F250s really got no better mileage than any other small block gasser of years past any brand. But my F150 5.0, similar size and loaded weight as the 250s got easily 3-4 mpg better.
5.0 ecoboost if hey could keep it together, would be an ideal hd pickup gasser I think.
Mo power than the 6.2 when you're hooked up heavy and heading uphill, smaller displacement and better mpgs for the routine daily driver miles that still comprise most of the miles driven even in HD pickups.

The question is why?


The little V6 turbo engine they are getting 365HP. How much more do you want or need? 400HP, 500HP? 600HP?

The only advantage is duty cycle. That's all.

I drove a turbo V8 for many years as my daily driver. A lot of concessions and not many advantages.

They used a lot of fuel. (13 average in a 3000 lb car.)
The engine was hard to keep cool.
The turbo would chew up the oil pretty quickly.
The engine compartment would get really HOT.
It wanted good fuel, not the cheap stuff and that was expensive.

A few of these problems can be mitigated with modern tech. Some are still problems though.

Just think of this: with a 6.0 liter engine at 15 lbs of boost will burn as much fuel as a 12 liter gasoline engine at full throttle! I'm here to tell you; that's a BUNCH! :E

Boils down to engineering EVERYTHING correctly for a turbo on such a
small displacement engine...

Power on any ICE equates to PSI on the piston.

Larger displacement will have a larger dia piston, therefore does NOT
need the PSI needed to make similar/same power from a small displacement
ICE

So, the amounts of stress and HEAT on that tiny displacement will need
much higher design margins than on the bigger displacement

Since smaller (and most cases half) displacement, it also has less
surface area to reject the larger amounts of heat generated per square inch

Why the EcoBoost, from my reading, has an engine oil squirt to the
bottom of the pistons to aid in rejecting heat from the pistons

The block/crank/rods/etc all have to be bigger both to handle the larger
PSI and thermal loading (wick it away quick enough).

Am assuming the head is aluminum, so it has to have much thicker sections
for the higher PSI's and heat rejection properties

Those are just the basic's off the top of my head...there should be
many, many more attributes designed that is invisible to us outside
of the design team

For me, the jury is still out on this and waiting for info to start
flowing on the rebuild of these engines. Key will be whether the block
and head can be just as easily...or will they find micro cracks...

OF course all my comments are for a gasser...and would love to stuff
in forced fed system for my big block, but that is still in the noodling
stages...OEMs won't because of the horrible MPG it will get while in
boost

rhagfo wrote:
Think about it, a 3.5 EB gets about 10 MPG towing about 8,000#...

Say it aint so :E
That's not what Ford leads you to believe when they're selling 'em ;)

I don't believe CAFE standards apply to 3/4 and bigger trucks.

As for a turbo in an HD truck, I would wonder about the longevity of something like that, especially in a smaller motor. While the 3.5L EB is by all accounts a great motor, can it hold up pulling heavy loads on a regular basis for 200,000+ miles in a 3/4 ton commercially used truck?

As stated above mileage would suck! Think about it, a 3.5 EB gets about 10 MPG towing about 8,000#, what do you think a 6.2 would get towing 14,000# to 16,000#?