By Bengt Halvorson





A couple of years ago, General Motors introduced a new-generation 3.6-liter direct-injection V6—beating its Detroit rivals, and most other automakers, to market with a DI engine. Between the Los Angeles and Detroit auto shows, Ford has introduced a pair of all-new V-6 and V-8 engines, slated for a wide range of applications and the V-6 making more power and torque than that GM V-6. But neither of the Ford engines employ DI.
So, we asked a powertrain expert at Ford, why is this? The answer, surprisingly, is that while we've been led for years to assume that direct injection is always a step ahead for fuel economy and emissions, in many cases it's not—especially when considering cost and complexity, and how the technology will pair with other innovations.
"When the program started, it [the new Duratec in the Mustang] was a direct-injection engine," said Greg T. Johnson, a powertrain integration manager whose responsibilities include both engines. But according to Johnson, Ford powertrain engineers eventually realized that leaving the DI aspect out of the design allowed charge-cooling advantages—allowing engineers to better optimize intake air temps for fuel economy, power, and emissions.
Typically, direct injection allows better control over knock, enabling a higher compression ratio, which does help optimize combustion. "Yeah, it helped us a little bit with knock, but it wasn't that much for all the cost," said Johnson, referring to all the more expensive parts, such as high-pressure fuel-system components, needed for DI. Ford even brought a DI version of the engine through to the point of running prototypes, "but in the end it didn't make business sense," Johnson summed.
The strategy—instead optimizing the new Ti-VCT system and emphasizing breathing—paid off. Having the extra leeway with breathing allowed both engines to put out more power and torque than rival direct-injection engines, while the variable valvetrain boosts efficiency with low load. The new Ford Duratec 37 produces 305 horsepower and 280 pound-feet, while GM's 3.6-liter direct-injected V-6 makes 280 to 304 hp, and 266 to 273 lb-ft, depending on the application.
The new 5.0-liter V-8 in the 2011 Mustang GT likewise has Ti-VCT and some of the same design attributes, according to Johnson (though with a number of racing oriented enhancements we report on here). It also makes more than many same-size or slightly larger V-8s, at 412 horsepower and 390 pound-feet of torque.
Fuel economy, too, is a strong point, with the V-6 expected to yield up to 30 mpg on the highway in the 2011 Ford Mustang and up to 25 mpg on the highway in the 2011 Lincoln MKX (and anticipated for the 2011 Ford Edge). GM's direct-injected V-6 achieves 18/29, at best, in the 2010 Chevrolet Camaro and up to 17/24 mpg in the (admittedly larger) Buick Enclave.
The new 5.0-liter V-8 is also expected to be quite fuel-efficient, with ratings up to 25 mpg highway in the 2011 Ford Mustang GT.
The 2.0-liter, naturally aspirated four-cylinder engine being introduced for the Ford Focus does have DI. According to Johnson, there are no plans to add direct injection to normally aspirated V-6 or V-8 engines, but we will continue to see direct injection in all EcoBoost engines because they are very knock limited and the extra measure of DI helps.
Undoubtedly, it depends who you ask. But maybe DI isn't the very worthwhile upgrade it's often touted to be.

 

I assume the 2011 GT500 would be a boosted Coyote with DI
LJS

 

Not so soon. Maybe next gen, but 2011 GT500 will be Al S/C 5.4L

And thanks for the article TN, it shows how one technological advancement does not fit all applications

 

2011 GT500 will use a revised version of the existing 5.4L with an aluminum block.

 

So..... boosted Duratec 3.7... or EcoBoost 3.5? Which would be "better"? Sounds like it would be pretty much a wash if they could control the knock in the Duratec.

 

That, combined with EPAS, might allow Ford to sidestep the Gas Guzzler tax.

 

cost/benefit for NA engines didn't quite work out. makes sense to reserve it for FI applications. still waiting for Ford to be the first to use a frickin' laser beam ignition system to the market. mwahahahahaha!

 

that 5.0 will be called the Mako cause it will have frigg'n laser beams on its heads

 

Interesting read. I was wondering why Ford didn't put DI on the new 5.0 engine. Now I know! Thanks for posting!

 

DI ftw.

 

lets just get camless solenoid valves already!!

 

within 5-10 years DI will be the new norm. DI is still in its infancy and costs a lot to produce. as the tech gets better it will be more efficient and cheap.

 

I think Mercedes gave that a try and concluded it wasn't worth the effort at this time, IIRC the system required a 24 or 48 volt charging system to operate without a hiccup.

The idea is awesome though, an engine that effectively has an infinite number of "cam profiles", the elimination of the throttle valve for reduced pumping losses, somewhat reduced mechanical complexitiy since there is no need for a cam drive or camshafts.

 

Not in this regard, apparently. Therefore, Ti-VCT FTW.

 

It's the future

 

I still am skeptical. There are a few other manufactures that refute what Ford stated in the article. For example, look at the power gains that the n/a Porsche engines recently saw. This sounds like another excuse for Ford, much like what was release why a SRA wasn't used in the past.....COST!

 

My thoughts exactly. Bottom line is cost, regardless how they try to play it down. They did their job at being 2% smarter than the public to eat it all up.

 

I'm not sure who among us is in any position to refute Ford's above claim that DI isn't the "Holy Grail" some make it out to be. Looking at the comparisons they make, Ford definitely presents a strong case, IMO.

The V6 Mustang will have 305 horsepower and be capable of up to 30 MPG; the GT, a 412 horsepower 5.0L that's capable of up to 25 MPG. The 2011 model year brings significant upgrades in handling, braking, driveability, refinement, etc -- this is on top of a car that's just about universally-praised in terms of driving dynamics and handling (the 2010 Mustang GT Track Pack). DI will be the norm on every engine, I have no doubt. Until then, I'm more than happy with what they've got in store for the Mustang.

 

The GM models that are being compared are also considerably heavier. Weight plays a critical role in fuel economy. It seems that Ford did a great job with the VVT and heads. Direct Injection is proven to add hp, increase fuel economy, and decrease emissions. Maybe Ford is holding out for a near future hp bump to keep the lineup fresh.

 

Spot on. And to add to that, the numbers speak for themselves...

Compare the new 5 litre's outputs to other big name units from the industry!

Ferrari's 458 from it's 4.5 litre, 9000rpm d.i. V8, has 120Nm/litre.
Mustang (2011) Mustang GT, 105.8Nm/litre.
Merc's SLS AMG is powered by a 6208cc V8 engine, called the M159, has 104.8Nm/litre.
Porsche's d.i. 4.8 litre V8 in the Panamera has 104.2Nm/litre.
Jaguar's new d.i. 5 litre V8, 102Nm/litre.
Lexus 5 litre V8, 101.7Nm/litre.

All the above are direct injected, except for the Ford motor. Now, that is one very big statement.

And whoever thinks "oh but it's only got 412hp", sit back a little while and wait for more news on what this little bent 8 can do in some SE models, 412hp is only base!
450HP+ is a walk in the park, that's without upsetting the hippies, too.