Why no Ecoboost in the F250?

[deezler]

Why pushrod with variable cam timing, and sequential turbos without crazy boost, and no complex variable compression ratio ?

I mean, if you want an efficient low speed engine, pushrods will do fine. But why add variable valve timing (that enables a work truck engine characteristic at low rpm, and racing engine characteristic at high rpm) to such engine ? Or add a 2nd turbo, which you only need to spool up the first turbo when its very oversized in order to secure high rpm peak horsepower ?

Variable timing is the bee's knees, man. Enables much nicer and more efficient combustion across a wide array of load and speed conditions. Like GM does with the small blocks. Proven tech.

The turbo setup is debatable, agreed. But pairing a small turbo with a large one means you can get excellent low end spool and barely notice any turbo lag (IE very quick to making 4-6 psi) and still have a huge surge of high rpm power. I want to have and eat the cake. Just dreaming, though.

Variable compression ratio typically means and ENTIRE extra spinning shaft and an extra connecting rod (with two bearings each) for each cylinder, plus multiple actuators and sensors with a complex control strategy. It might work fine. Or might be a disaster. Nissan was pretty proud of their setup for the Inifiti motors, but it maybe added 1mpg for an expensive engine and vehicle in a segment where nobody even cared.

 

[deezler]

Well those 6L’s were never nothing to brag about.

Ever notice how the gas crowd is always comparing a new gasser to an older model diesel?

Diesels have improved in technology, too
We’ve got 3 you can get in a pickup at 400HP and ~900 TQ now, so lets compare them as they exist now, or back then. Not now against back then.

Not me, I have been comparing fuel economy of brand new gassers to the current diesels. My point being that the newest gas engines coupled with the 8 and 10 speed transmissions have made a giant leap in both power delivery, safe towing capacity, and real-world fuel economy. The newest diesels might have loads of tech for smooth operation across a wide powerband of massive torque, but they ain't any more fuel efficient. They're often worse now.

Co worker of mine just scrimped his pennies to plunk down 70k on a new ram 2500HD cummins. Gets substantially worse mpg than his trusty and rusty old 2003 cummins, plus needs DEF added every 3000 miles or so. Very thirsty for both diesel and DEF. Plus $200+ of filters every 10k miles (fuel and oil). Just kinda stupid, IMO.

 

[5030]

The more complex any engine becomes, the more chance for failure and the Eco-Boost engines are noted for timing chain failures plus they require regular oil changes like very 5K miles or they puke.

Far as GM and VVT and their cylinder cut out, the only thing that does is cause the motor to consume oil. I installed a Range delete on my wife's Suburban, first thing after she got it used. Previous owner was adding a quart every 1K miles. It consumes no oil now.

 

[deezler]

So, nope: the EcoBoost is still very, very far away from the cylinder fill grades, compression end temperatures, and peak combustion pressures of modern diesels, whether light duty V8s or heavy duty onroad or offroad engines. Diesel cycle and Otto cycle engines still really arent in the same league.

You are really good at your napkin calculations, I'll give you that.
What I am telling you, is that I have measured the cylinder pressures in each of these engines directly myself, with calibrated piezoquartz transducers. Stock the Ecoboost is much lower in stock power level, ~125 bar PCP. But aftermarket calibrations surely push it significantly higher; haven't measured this directly myself but 150 bar is not an unreasonable guess. When the scorpion is running under 165 bar, I would call that close. no?

One thing to keep in mind is that PCP does not work linearly with power/torque, especially when comparing gasoline combustion (peaky) to diesel (more broad, especially with multiple injections to spread it out). So at the same PCP, a diesel engine can be making a higher mean effective pressure (BMEP, = torque).

 

[Hay Dude]

Not me, I have been comparing fuel economy of brand new gassers to the current diesels. My point being that the newest gas engines coupled with the 8 and 10 speed transmissions have made a giant leap in both power delivery, safe towing capacity, and real-world fuel economy. The newest diesels might have loads of tech for smooth operation across a wide powerband of massive torque, but they ain't any more fuel efficient. They're often worse now.

Co worker of mine just scrimped his pennies to plunk down 70k on a new ram 2500HD cummins. Gets substantially worse mpg than his trusty and rusty old 2003 cummins, plus needs DEF added every 3000 miles or so. Very thirsty for both diesel and DEF. Plus $200+ of filters every 10k miles (fuel and oil). Just kinda stupid, IMO.

I bet I tow more than him (towing uses more DEF than empty-more loading, more DEF) and I barely use 2.5 gallon jug a month. $11 at walMart. Big whup.
BTW: He will LOVE that truck. None better.

Your friends new Ram has almost double the HP & TQ as his 2003.
Aint no free lunch.

Stupid? lol.….Buying a gas truck that gets 5MPG fully loaded versus 9, or in my case I would have to tow much smaller loads because gas GCWR sucks, would be stupid.

You’re just trying to justify your gas truck purchase by making other people feel bad for buying a diesel truck. I get it. I once talked down diesels like 25 years ago. Then I towed with one and I was sold forever. Sure the DEF/DPF sucks. It’s a setback, but they have improved somewhat. Let’s also not forget, the premium power gas engine is also an upgrade you must pay extra for. It‘s not the base engine in all trucks.

You roll your way….I’ll roll mine. I’ll just be pulling double the weight and getting 3 more MPG.

 

[deezler]

Lol. I only bought a gas truck because I couldn't afford a diesel, if I'm being completely honest. My '03 6.0L gas was 13k in great shape, rust free 88k miles. Whereas a dmax would have been closer to 20 for the same condition (back in 2015). I drove a diesel VW for 10 years and loved the heck out of it. Once modded it was as fast as a GTI but with 55mpg.

But then I built a house in the wood and needed a truck. Once I had kids and was glad I didn't need to poison them each time they rode along, too. (well, not poison them quite as much, I suppose).

I'm not trying to defend myself for anything, just offering my perspective as an industry insider who dyno tests prototype engines. Unfortunately we only get access to those engines for which my company (supplier) has been awarded specific business, so I don't get into everything. Just saw that ford has a 6.8L gas V8 coming out shortly... I had no idea, since we have no powertrain parts in it, apparently. Should be a nice upgrade from the 6.2

 

[crashz]

You'll all tremble when I get my 87 6.2L diesel back on the road. 130HP and just enough torque to pull a doughnut from a paper bag!

 

[timswi]

You'll all tremble when I get my 87 6.2L diesel back on the road. 130HP and just enough torque to pull a doughnut from a paper bag!

Dunno--I had a 1989 2500 Suburban 4x4 with a 6.2. Aside from eating glow plugs, I kinda liked that thing. No hot rod to be sure but it did fine for what it was..Mid 20's on the highway wasn't bad. Water pump replacement was a royal PITA tho.

 

[BravoXray]

I bought a new '79 Chevy pickup with the 5.7L diesel, what a POS it turned out to be. When it wasn't in the shop, it would get ~25 mpg, but it took a mile and a half to get it up to 60 mph. The first two years I owned it, it was in the shop for over six months. Head gaskets, injection pump and oil leaks were most common problems.
When if was finally out of the extended warranty, I jerked the diesel out and put in a junkyard 350 that I freshened up. Ran it until '93, when a neighbor made me an offer I couldn't refuse, and I bought a nice '91 F150.

 

[Eagle1]

Now you need a scanner to reset the oil change light.... let alone do some real work on a new truck.