2015 Ford F-150 unveiled

Bionic Man wrote:
The weight savings and safety features are the big advancements. Put me in the camp of the other posters that the small turbocharged engines are not a selling point. They are equaled in power & fuel economy by competitors.

Kind of surprised that they are staying with a 6 speed transmission and that they aren't offering a small diesel.

They are pushing the envelope forward more than the new Silverado.

jerem0621 wrote:
I'm sold too. Can't wait to test drive one. That new 2.7 is interesting. Found some speculation that it will probably be in the 330 hp range with 360-370 ish lb ft of tq. That's more hp than my old 99 6.8 V10 and nearly as much tq.

Thanks!

Jeremiah

Gentlemen,

The distinct possibility exists that Ford may finally go beyond other standard OEM thrift technologies. Ford is also taking advantage of automatic start/stop technology similar to Ram and GM, but Ford is applying it to an already super fuel efficient engine using turbo tech.

Quote of the J.D. Power review stated in the Under The Hood section:

"For 2015, Ford offers two EcoBoost engine options, each equipped with active grille shutters. One of them is the familiar 3.5-liter twin-turbocharged V-6, available in the current version of the F-150. The other is a new 2.7-liter twin-turbo V-6 equipped with automatic start/stop technology that is designed to cease operation whenever the truck is placed in 4WD or is trailering. This new EcoBoost engine was used in a disguised 2015 F-150 to compete in the 2013 running of the Baja 1000, completing the 883-mile race without incident"

One of the things I personally do not understand well is how automatic start/stop technology can help much, but it obviously does. My question is with pumping losses which would seem to still exist even if a cylinder did not have fuel to fire. A V-8, for instance, would still be "dragging" 4 extra pistons along whether or not they contributed to power. In my mind I finally resolved this by thinking that when only 4 cylinders fire, the thottle must be open further to maintain speed and this therefore reduces vacuum. Under high vacuum, the unequal lack of topside piston pressure as opposed to bottom crankcase atmospheric pressure is part of normal pumping losses, but an open throttle allows closer-to-atmospheric pressure topside, same as nominal crankcase pressure bottomside. I'm guessing perhaps that is the sole thrift gain.

Diesels take advantage of this lower-pumping-loss principle by not having throttles controlling engine speed (power output), but rather by adding or subtracting fuel only. Diesel high compression has no trouble igniting lean mixtures as opposed to gasoline spark plugs which may fail to spark across a "dry" gap. An interesting aspect is that some turbo gasoline engines can now achieve the same economy by incorporating DI (direct injection) to spray fuel only towards the end of the compression stroke and cause a SC (stratified charge). In other words the fuel "cloud" is much richer near the spark plug and easily fires in spite of an extraordinary lean mix overall. The most interesting aspect is that a throttle is no longer necessary, now allowing a gasoline engine to match the pumping efficiency of diesels for the first time on production engines. I saw this touted, but have no idea who is actually using this tech.

Recently I was involved in a RV.NET thread discussing whether TC (turbo-charging) can equal the thrift of NA (naturally aspirated) engines. One of our very knowledgable forum members, who has a lot of actual hands-on experience in turboed race engines, felt that all boost chargers, including turbo, need additional fuel just to power the compressor. I thought turbos are different in that they do extract additional heat energy from the fuel (essentially free energy) noted by supposedly cooler-than-normal waste exhaust vapor (per lb/per identical hp). I imagine this "recovered free energy" is then theoretically used to reduce pumping losses in the ICE (internal combustion engine) thereby slightly improving a turboed engine over a naturally aspirated counterpart.

I've had a hard time finding references on the internet, to support my argument (above paragraph), stating that turbos can be more efficient than natural intake aspiration, but I did finally find, on my computer, this past 2006 interview link (quoted below) from Martin Verschoor, Technical Director of Garrett Engine Boosting Systems. Unfortunately for me, there is no mention of recovered energy. It does imply that turbocharging is thriftier, but of course Garrett would be biased that way. Perhaps more significant, Ford must feel the same way and has staked a lot of money on it. So far there appears no irrevocable truth either way.

above link partial QUOTE:

"What needs to done to make turbochargers more popular in the States?

I think turbos need to be tuned to “drivability” more than sheer horsepower. If you look at the turbo applications in the United States, fifteen years ago, they were basically highly souped-up, highly boosted, standard engines. If you take a different approach and used turbo-charging to increase the low-end of the engine, you’ll actually see better drivability from a two-liter engine than a three liter (non-turboed) engine: more torque, more low-end response, higher top end and better fuel consumption. American OEMs need to realize you don’t use turbos for horsepower alone, but to enhance the total driving experience.

You can make the engine 30 to 35 percent smaller, which takes all the weight away and you might use fewer cylinders and overall you have a lighter drive train."

Wes
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