Update 2: Cummins, Feds Developing Four-Cylinder Diesel for Nissan Titan

Cummins, Feds Developing Four-Cylinder Diesel for Nissan Titan
Photos by Cummins, Nissan as published by the U.S. Department of Energy

Cummins is developing a high-efficiency inline-four-cylinder diesel engine with money from the U.S. Department of Energy and in partnership with Nissan for demonstration in the Titan light-duty pickup truck. The project was announced at the DOE’s 2011 Merit Review in Washington, D.C..

Most half-ton truck makers are betting on small-displacement direct-injection gasoline engines to meet future fuel economy regulations, but Cummins expects its small displacement oil burner to get 40 percent better fuel economy over current light-duty V-8 truck engines. The Cummins average fuel economy target for this new diesel engine is 28 mpg while meeting tough U.S. Tier 2 Bin 2 emissions limits, according to the presentation.

Getting 28 mpg combined mileage could mean more than 30 mpg highway, by our estimate, which could help Nissan meet strong new EPA regulations that will raise fleet fuel efficiency standards for light trucks and SUVs to 30 mpg by 2016. The standard for passenger cars is set at 39 mpg by 2016.

Prototype Cummins four-cylinder inline diesel in a current Nissan Titan's engine bay.

Though the project started in September, Nissan and Cummins have already built a prototype version of the four-cylinder diesel and installed it in a current-generation Titan mule for drive testing. Pictures of the engine show four high-pressure fuel rails feeding the engine’s cylinders.

Four cylinders might not seem like enough to power a full-size pickup but that architecture would be ideal to meet fuel economy goals while delivering almost as much torque as some small displacement gasoline V-8s.

The engine has a 2.8-liter displacement (170 cubic inches). Initial power figures on the engine dyno have the mule test engine producing 350 pounds-feet of torque at around 1,800 rpm. A chart in the presentation shows targeted power levels to be approximately 220 horsepower and 380 pounds-feet.

The engine is a derivative of the four-cylinder ISF architecture that Cummins builds overseas, with 2.8-liter and 3.8-liter displacements, according to a Cummins spokesman. The overseas 3.8-liter is rated at 168 horsepower and 443 pounds-feet of torque.

Side profile CAD rendering of the prototype I-4. Note the EGR cooler (purple) and turbo just below it. The front of the engine is to the right.

Innovations highlighted by Cummins in their presentation include the use of high-strength steel pistons instead of conventional aluminum pistons. Steel pistons can handle high power loads with a shorter stroke, which also helps reduce the overall height of the engine for improved underhood packaging. Cummins is also studying the use of variable valve technology, according to the presentation.

To meet U.S. clean-diesel standards, the 2.8 would use diesel exhaust fluid to scrub nitrogen oxide emissions, like Ford and GM use today in their heavy-duty diesel pickups. It would also feature a so-called passive NOx storage system that would capture and hold NOx during cold starts, releasing the gas when temperatures rise to levels of max efficiency for DEF. The passive system would save fuel used today to jumpstart NOx scrubbing when the system is cold.

The total size of the Cummins light-duty clean diesel project is a $30 million effort, with the DOE contributing $15 million. The program is scheduled to run through September 2014, the year in which we expect the next-generation Titan to debut.

Nissan has been working with Cummins for several years studying the potential for a light-duty diesel in the Titan.

The current Nissan Titan is only available with a 5.6-liter V-8 gas engine that's rated at 13/18 mpg city/highway and 15 mpg combined fuel economy.

Stay tuned for more information as it develops.


[Sources: Cummins, U.S. Department of Energy]

Update 2: May-19, 2011 10:15 pm Pacific

We originally reported that "LA-4" was the codename for the engine. That's incorrect. LA-4 refers to the EPA's Urban Dynamometer Driving Schedule, also known as "the city test." It represents city driving conditions and is used for light-duty vehicle testing.

Cummins says it plans to demonstrate the diesel in a truck chassis using the EPA's Federal Test Procedures (FTP) for emissions certification at Tier 2 Bin 5 levels – used by today's clean diesels – by December 2013 and at Tier 2 Bin 2 levels by September 2014.


LA-4 refers to EPA dyno test procedure for city driving conditions, FTP = EPA Federal Test Procedure, A/T = Aftertreatment (emissions cleaning technologies for soot, NOx, etc.)

We also heard back via e-mail from Nissan spokesman John Schilling after we called the company asking for comment.

"This isn't something we are going to discuss right now," Schilling said. "We don't discuss future product plans including Titan."


Update 1: May-19, 2011 12:05 pm Pacific

In the first version of this post, we said the Cummins I-4 diesel would meet Tier 2 Bin 5 emissions standards. Cummins says it expects to meet Tier 2 Bin 2 emissions standards with the 2.8-liter engine.

Tier 2 Bin 2 is a stricter standard than the current Tier 2 Bin 5 rules required to qualify as a "clean diesel." Tier 2 Bin 2 standards are the same for internal combustion engines regardless of fuel type (gasoline or diesel). It's equivalent to California's super-ultra-low-emission-vehicle (SULEV) standard.

We've also confirmed with a Cummins spokesman that the 2.8-liter diesel is a derivative of the 2.8 that Cummins builds overseas.


@ Mike Levine

"Some more data, as I continue to review the presentation.

A chart shows targeted power levels to be approximately 220 horsepower and 380 pounds-feet.

Highway fuel economy could be as high as 34.3 mpg."

Target hwy fuel economy as high as 34 mpg! We don't even have a compact truck in the US that gets mid 20's.

Great story, however I would love to see some innovation in the compact/midsize truck market. If they can potential get ~34 mpg out of a full size truck (that is price competitive) what can a midsize get?

@Mike Levine

any word if/ when Nissan will start to use their direct injected 5.6L w/ the seven speed tran found in the QX56 ?

also, has there been any updates on the rumor the titan/ NV vans were getting the new cummins 5 Liter V8 as an HD option?

I like the idea of this engine or any small diesel in a 1/2 ton a lot, but I think this one would be a better fit application wise in the frontier.

I have to agree with Big Bob and BigAssGas. This all comes down to price.

I sell in the Fleet & Commercial Department of a Chevy dealer. Everyone wants better fuel mileage, but 95% of the people I sell to would not be able to break even on fuel with a diesel. They don't drive enough miles or haul enough payload to make it worth it.

Right now, diesel and gas are the same price at the station across the street from me ($3.99). If you increase your fuel mileage from 18 (current estimated hwy mileage of a 4wd long box reg cab Silverado 1500) to 30mpg, and the diesel engine is another $5k (currently Duramax/Allison combo is a $7,388 add) it would take roughly 57,500 miles to break even. If it were the same cost premium for the small diesel as it is for the current Duramax/Alli combo it would take almost 85k miles. This does not include any additional costs for DEF, etc that come with a diesel engine.

I am sure that some small diesels will get sold if/when they come to market. I just don't think they are the answer with the current costs of fuel and the vehicle. Obviously if the cost of the vehicle could come down dramatically or the cost of fuel increases dramatically it would be an easier sell but not currently.

Just my opinions.

220 horsepower and 380 pounds-feet

That would be perfect for a 1/2 ton truck. That is 2/3 of the output of my 05 Cummins (325/610) which has plenty of power for towing the Rocky Mountains.

I prefer to do as much of my driving as possible below 2500 rpm (gas or diesel), so torque is king. The 350-400 hp that modern V8s brag about is at 5000-6000 rpm! If a daily driven pickup engine spends much time spinning that fast something is wrong!

I assume the $15 million Cummins got is to help them figure out how to make a diesel fuel efficient in spite of the draconian emissions. I really hope this project goes farther than the last Cummins DOE project that teased us for years with demonstartions of light duty V6 and V8 diesels shown in Dodge Durangos and Rams.

As others said in previous comments, Ford, Chevy and Dodge (with the help of Cummins!) have ready half ton V8 diesel ready, so maybe this is the time to stuff them in?
Mike, I can't understand why Nissan and Cummins consentrate on an in-line 4? Is it because its cheaper to buy and to run than a bigger v8 diesel? Should the Big three also swap for smaller in-line 4 Turbo-Diesels?
Great story Mike!

Think for a minute how amazing this would be if true. A full size truck getting 30+ mpg on the highway, while retaining most of the capability of a half ton. The old GM 6.5 produced similar power levels and certain vehicles with that engine were rated to tow 10,000 lbs. I'm not saying you'd want to do that, but this new diesel mated to a modern 6 speed auto would provide enough power for most truck buyers while returning mid-sized sedan mileage. If they could keep it south of $40k, they wouldn't be able to produce enough of them. Sign me up!

At least at this point, automakers should make a small diesel an option. I don't understand why it has taken so long. Here is my idea for engine choices: Inline 5 or 6 base gas engine(the new Ford V6 is the right track too), 3 to 4 liter small diesel, traditional gas V8 like a 5.3 or 5.0, and the big optional 4000 400 hp V8 for performance and top end trucks. I said this a few years ago and imagine the benefits in the commercial industry if companies only had to supply diesel to their fleet. I loved the 4.5 Duramax idea. Imagine the savings for the average consumer who wants to tow the camper or boat on the 3 hr drive 6 times a summer. 250000 almost guaranteed lifespan also.

@ Kestin
i agree i just do not think a small diesel is going to be the answer to better FE, simple reason is emissions that they require, diesel engines are a headache to maintain especially with all the new emission standards and all the censors they put in to achieve that plus the extra upfront price, diesels have there place i feel do not belong in half tons

Nissan can plop it in other platforms, Cummins can sell it abroad. If it works, it'll sell and the costs will come down.

There's nothing fancy here. It's what the average 1/2 ton pickup consumer wants. German auto manufacturers are selling the crap out of deisel engines today. There's no reason pickup manufacturers can't enjoy the same success.

The goal for this engine is to be a mainstream engine that lifts pickup fleet fuel numbers. It ain't the trophy girl upgrade with the little engine label on the side of the pickup. 220/380 is what's needed. And 34mg will get much attention vs the EB's underwhelming 22mpg.

First post.

I love this web site.

The idea has merit. We need small diesel powered PU's. However I would have preferred a 4.0 I6 in the Titan. This smaller engine would be fantastic in the smaller Nissan PU.

What about cost?

I hope Nissan has learned from their mistakes with the Titan which was plagued with problems at the beginning. I have one, but I was not going to buy a Nissan Titan as replacement (due in 2014). The Ecoboost got my attention.

I give them credit (both Ford and Nissan) for thinking outside the box. All of us PU lovers will benefit in the long run.

This could really be a good thing to push all the automakers to adopt diesel technology into the whole line up.

Everyone keeps saying that 200hp was great in the 80's and 90's trucks. Does everyone remember that trucks weighed about 1000lbs less than they do now??? Do we remember that CrewCab trucks hardly existed???

Making a L/D diesel engine for a 1/2 ton truck isn't a big deal. Constantly changing diesel emissions regs are. CARB is already talking about tightening up their diesel regs even more, and banning most Commercial diesels from even driving in their state (if they cannot add CARBS approved emissions equipment, which, knowing CA, will change every few months).

This is why you haven't seen L/D diesel engines in 1/2 ton trucks yet. The manufacturers do not want to spend many 10's of millions in development and manufacturing, only to have the rules changed in a year, causing yet more 10's of millions od dollars in development. The bottom line at this time, would NEVER be in the black.

As for Tom saying this engine will make the Titan pass F-series sales (assuming it would ever make it to production). All I can say, is what planet are you on?? You think one engine would carry Titan sales from 1500-2000 a month, to 20,000-30,000 a month, overnight?? I want what you are smoking.

Cummins was developing a 5.0L ? diesel for chrysler in 2008 when the crap hit the fan. When chrysler went belly up Cummins said they would continue developing the engine. That was just after the bankrupty judge tore up the contract. I understood at the time that it was slated for the Ram 1500. GM and Ford were also touting a future 1/2 ton diesel before wall street/banks blew up the economy.
This article lists the engine as probable a 2.8 l engine. So, not the same one?? Or maybe Cummins did continue development and just downsized the displacement. I guess it doesn't matter as long as this Nissan gets Detroit gets off it's laurels and finally offers diesels more concerned with mileage than towing. I beleive that if Nissan offers a diesel then Chryler, Ford, and GM will Also. It's as though none of them want to be first. That seems shortsighted to me.
(jmo) Build them without DEF and say the heck with the CARB diesel NATZI.

@Robert Ryan. The US standards and the Euro standards focus on different pollutants. Passing Euro standards is no guarantee that it can pass US or CARB standards and vice versa. Put away your hate everything American for once.

This looks promising, but I'm more interested in seeing what the future designs of the Titan and Frontier look like. Would it kill Nissan to offer up a little tease?

It is amazing how 220 hp and 380 torque is now "perfect" for a half ton.

But when the 5.4 in the F-150 had 320 hp and 390 torque we were told it was so bad and so underpowered.

Make up your minds.

And from 1989-1993 the dodge cummins was 160hp/400fts.

Today's more modern engines are more efficent with optimal parameter controls, new turbo designs, efficient drivetrains, aerodynamics, thinner sheet metal, lighter materials, etc. There's no comparison and no argument as most consumers prefer safety to the old naiive designs.

As far as the govt changing rules? As with previous Cummins diesel engine devleopment, the us gov't is involved in this engine's development with a goal of future emission/fuel economy.

The bottom line- there're ain't no way to get there with direct injection turbo gas engines.

Add this engine with future lighter and stronger materials and you have a future path of fuel efficient pickups that can keep consumers and commercial vehicles moving.

It says it was for demonstration purposes only.

Maybe Gm backed off from the 4.5L dmax because it was still the old guard way of thinking: more hp/tq gets sales. They have no choice but to think of future suv/light duty pickup fuel economy goals.

I'm sure every company has things they can demonstrate. Putting them into a real truck and selling them isn't the same as a demonstration.

I'm all for it!! I might not buy one, but I really hope lots of other people would. I would love to see Nissan do this, and start to take sales from the Big Three. I believe that losing market share is the only way to get their attention and force them all to build their own diesel 1/2 ton. Hell I might even join in and buy one from Nissan, especially if it would put me closer to having that baby power stroke I have wanted for so long in my driveway! Besides everyone worrying what this engine is rated for stock, look at what the aftermarket is doing with the HD diesel's, it's amazing what an exhaust, tuning, and intake can produce with them. Power and efficiency are dramatically increased.

This Cummins motor, in a Titan, might help Nissan sell a couple hundred more Titans a year?

This Cummins motor, in a Ram 1500, would have helped Chrysler sell a couple thousand more Rams...a month?

I hope that Cummins is not expecting to make very much profit with this deal. Unless, Cummins makes Nissan sign a contract for a minimum of 10,000 units a year, or something like that, regardless if Nissan is only able to sell only 5,000 for the year.

Friends in the diesel biz steered me to this article - so, my first visit to the site.

Editorial and journalism side seems to be right on - and only a smattering of populist trolls. Phew!

Try looking over the USA, USA, USA-fence around your minds sometime, folks. Euro diesel emissions requirements are on the way to being higher than ours. They all have governments more serious about science and climate change than Congress ever will be.

Lots of suggestions - already exist outside the US, including Rangers with a diesel. Available in Brazil and Australia, too, I believe.

Manufacturers who stop crying in their beer and reach out to compete can still happen in the US. MVP got Chinese investors to come in and fund properly-sized RVs for the China market and they're now starting to export US-built RVs to China. Took over a closed Fleetwood plant.

@Jason: I'd say the reason 220 hp and 380 torque is acceptable in this case is because Cummins is targeting 28 mpg combined vs. 14 mpg combined for the 5.4-L V-8

Acceptable or meeting minimum requirements, I would agree with.

People were saying it was perfect.

Although it would get great mileage, it is far from perfect and I would hazard a guess it would probably come in dead last in a 2014/2015 shootout type of test.

I would agree now if we were talking the ford 4.4L , gm 4.5L or the cummins 5.0L then they would have my attention.

@ Kestin - agreed. I rarely ever see fleet trucks with diesel engines. No return on investment. The company my brother works for buys or leases several hundred trucks a year. They go on a 3 year or 60,000 mile cycle. they wave the warrranty and get an even better deal. His company's experience with trucks is that they turn to junk around the 60,000 mile mark. Those trucks are driven mostly off road. A fleet which drives mostly highways might see a return on investment, but a duty cycle would have to be closer to the 100,000 mile mark (or higher) for return on investment.

@ Gloria - I interpreted Tom's remark to mean that if the Titan had a Cummins diesel it would cut into Ford's sales enough to make them loose #1 spot.

@ toyboxrv - not sure where you see "hate" from Robert Ryan. I welcome his perspective.

I interpreted Tom's remark to mean that if the Titan had a Cummins diesel it would cut into Ford's sales enough to make them loose #1 spot. - Lou

Thanks for the laugh.

@Jason: "Although it would get great mileage, it is far from perfect and I would hazard a guess it would probably come in dead last in a 2014/2015 shootout type of test."

It all depends on how test results are weighted. If the gov't mandates 30mpg goals and/or gas is $6/gal, enthusiast-like hp/tq related tests would be obsolete. Manufacturers would be selling like-minded vehicles. Cummins could always add enthusiast tunes for small scale, margin consumer sales.

I had to compare hp/tq per liter displacement. They're pushing that motor to amazing comparative levels:

140hp/2.0L = 70
236tq/2.0L = 118

Ford 6.7L SD
400hp/6.7L = 60
800Tq/6.7 = 119

Cummins 2.8L
220hp/2.8L = 79
380tq/2.8L = 136

Sign me up. I'll buy one as soon as it gets of the line. In 2014 i'll be getting out of college! sweet.

What we need is smaller trucks, not big trucks with smaller engines. Bring back the compact pickups of the 80s!

The 4cyl is a smart move. With less components and a smaller displacement it will be less complicated, require less emissions equipment, and be less expensive than even the small v8 diesels Gm, Ford, and Cummins had developed. If the option price is low and the buyer can make it back at resale, than it becomes a much more enticing option.

The one big hurdle for this engine, as I've mentioned before, is the SAE J2807 towing standard. This standard requires trucks to be able to tow specific loads while timed. If the truck can't meet the required time, its towing rating would be reduced. With 220hp/380ft-lbs tq I doubt this truck will be a speed demon. More than likely, it's towing rating will be more comparable with typical V6 gas options and maybe small V8's rather than the max-tow V8's.

Nissan should update the VQ40 V6.
Install variable exhaust valve timing, VVEL.
300hp 300ft-lbs, with the JATCO 7 speed automatic.

Very competent 'base' performance in the Titan, and outstanding performance in the Frontier.

At least use a BIG 4 cylinder, 3.8 liters please.

@Jason aren't those numbers when running on E85 as well? I've heard some pretty terrible mileage figures in that configuration, even worse than Mike's 14 combined stated above.

It'll be interesting to see what happens. With the power rating, I don't see this as a 3.5L EcoBoost compeitor, but perhaps this will push Ford to offer the 2.0L EcoBoost in the F-150 for those that don't need big power and would trade it for additional fuel economy.

The first 1/2 ton or smaller truck to the market with a diesel will get my money. Bring it on Nissan and Cummins. Thanks

Great to see this. The most important take away here in my view is that the gov't is involved and embracing this. Perhaps we can quit wasting money now on hybrids and ethanol subsidies. Diesel is the only viable option to meet new mileage standards now and the gov't is fully capable of making diesel costs much more attractive for a truck buyer. As Ken says, there's no other way. The EB had me worried that we would never come to our senses.

EGR before intercooler seems like a really bad idea...

The 2.0L EB equipped Taurus with 237hp/250tq has an estimated 31mpg hwy so that ain't gonna get it done with mpg or capability in a half ton pickup.

Direct injection gas turbo engines give slight fuel economy gains as long as you don't work them. It's a good temporary stepping stone to a dead end.

this is great news i cant wait id like to swap one in to my colorado

anyone ever think about running other fuel then just diesel fuel if i can get this ill be running bio from my home much cheaper then diesel and just wait till the aftermarket gets after this thing it could be one great powerhouse of an engine

"If the gov't mandates 30mpg goals and/or gas is $6/gal, enthusiast-like hp/tq related tests would be obsolete..."

The 30 mpg mandate for trucks is the overall fleet average and counts trucks, suv's, mini vans, and cross-overs.

If Obama is not relected, gas will go back down to $1.60 or less by the time this diesel engine comes to market.

And the disparity between regular and diesel prices could rise gain. In December 2008 regular gas was $1.60 and diesel was $2.40

hp and tq tests are never going away.

@Ken they are already selling this engine overseas, my guess would in South America, i.e Euro 111 and EuroIV. Ford runs Cummins engines in their Cargo trucks in Brazil and their F4000 pickups.The current Navarra(4,500lb Frontier) runs a 3 Litre Renault derived 230hp 405lbs ft of torque diesel
@ Lou thanks for the comment. The poster thnks if you do something different outside the US, you must be "anti-american" whatever that means.

The engine is cleaner burning than I first reported. It meets Tier 2 Bin 2 standards, not Tier 2 Bin 5. That makes it as clean as a gasoline engine. Not an easy feat if they can pull it off.

@Mike Levine, I hope they do. Maybe just maybe, Ford, GM , Chrysler and Toyota can follow suit. If you want US Pickups to be competitive outside the US, this is a good start. Although I would have liked to see the 3 Litre in a midsize and maybe a 4.5 Litre as an option in a full size.

I have always wanted a diesel pickup but like many people don't need a full size pickup. This would be perfect. To the guys who say the horsepower isn't enough, how much more power do you need out of a half ton truck?


I have to agree with others I think somewhere between 3.5L and 4.0L would be better and I would like 260hp and 400lb ft at a minimum.

@Mike Levine,

T2B2 really? That would be phenomenal if achieved.

As far as being "as clean as a gasoline engine", I'm aware of a few hybrid SUVs that are certified SULEV in California, and thus would be EPA-certified T2B2, but I'm not aware of any full-sized gasoline pickup trucks that have hit T2B2 yet. Are you aware of any?

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