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.


GM is building a brand new plant here in Baltimore where they are going to make Electric motors for Full size SUV's and Pickup's, so I'm sure GM is working on something for its trucks.

Just when I swore off foriegn vehicles !!! I currently own a 2005 Titan and it really likes the gas pump !!! One waring about Nissan I am experienceing at the moment. I need to replace front passenger seat foam. Nissan will not sell it without the occupant sensor, $880+ is too expensive for just the foam, they should sell it separately !!

If GM would put an Isuzu Diesel in a Colorado, I would buy one today !!

@wxman: The only T2B2 vehicles I know of are small car hybrids, like the Honda Civic Hybrid.

this is awesome news... silence to those who complain that it is a Nissan... this is a step in the right direction to those of us who want a diesel in a half ton or smaller!

I can't wait. In fact, I HOPE this goes into full production. And with that, I hope the rest of the industry here in NA follows suit!

This is really great news. It will push everybody to
follow. TR Ram Life Style Truck with 3L VM Motori,
I am still waiting for and not buying any old garbage, even my 2004 Durango is dying slowly and painfully.

this is a good news ,maybe the order truck company do the same except ford whit the new gas engine to much to lose

Fuel economy and passes T2B2, Saw-weet!. That'll shut down the diesel emission naysayers.

Hopefully other manufacturers are taking notes otherwise they'll lose half-ton pickup marketshare.

I think the people complaining about the cost differential vs a gasoline engine are forgetting the fines for not meeting your CAFE averages.

Each one of these light duty diesel pickups will give the manufacturer a slight reprieve in terms of fuel efficiency. And a big one as regards CAFE standards.

Quite frankly I wouldn't be surprised to see Ford and GM bringing their smaller truck offerings from overseas, complete with the four cylinder sub 3.0 liter diesel engines specifically for the purpose of meeting/ beating the truck CAFE standard.

I rather like the diesel Ford Ranger that is on sale worldwide...

How cool would it be if this ended up in the Jeep pickup. Yep.

@Lou. If you spent much time on the forums here or those over at GM Inside News, you would know how Robert is constantly looking at anything from America in a negative manner. We just can't live up to his standards here.

His comment above is typical of his perspective. He generally looks at anything done elsewhere as better than what Americans do. It is never different strokes for different folks, it's non American trucks serve people's needs better than anything from Detroit. Every comment he makes is from that perspective.

If the Cummins from the article does in fact meet those emissions standards, it is way better than any diesel around.

Do you guys remember when Mahindra diesel was supposed to get 30 mpg? Then it came back at 19/21, nowhere near the 30 mpg they claimed. Just throwing that out there.

Mahindra TR40 Rated at a Disappointing 19/21 MPG


Where have you been to think that the gm was the best selling truck until last year? Are you serious?

380 lb-ft is only 40lb-ft from the Eco Boost and with Max Tow, that's rated to pull 10,300 lbs. This thing should be able to Tow 8-9k no problem. If you need more, you should be driving a 3/4 ton.....

What Bizzaro world am I living in that Nissan is going to put a diesel in a non-heavy duty truck and Dodge is going to have a truck based off a minivan?

The current Titan tows 7400 lbs without the premium utility package.

This Cummins motor has 120 pounds less horse power and 5 less torque so it probably won't be the premium engine.

So why would it be able to tow more than 7400 lbs if it has significantly less hp and the towing regs are getting stricter?

The max this will probably tow is in the 5000-6000 lbs range.

Add in passengers and anything in the bed and actual towing may be closer to 4000 lbs.

I'm tired of hearing you should be driving a 3/4 ton. That has been beaten to death.

@ toyboxrv - I don't see it the same way as you do.

Again, this engine isn't intended to be a heavy tower, it's intended to get good mpg and increase a manufacturer's fleet MPGs, its a mainstream engine intended for the masses.

@ Dave
The issue with the Mahindra is its gearing in relation to its engine. That thing is just running strung-out in order to meet the "Specs" that Mahindra keeps talking about (Insane payload of about 2000 lbs and tow capacity blah blah blah). Pickuptrucks.com did an article on some other tiny diesel pickup that also got horrid fuel mileage if you went above 45 mph because of its gearing. The Mahindra's fuel mileage only shows how inept/inexperienced the company is when it comes to playing with the other players in America's Market. Look at the Toureg 2, that thing weighs about the same as an F-150, and it achieves 25+ mpg highway with a 3.0 liter v6 diesel. In contrast, the VR6 on that beast can maybe get 20mpg on a very good day, but I've heard 18mpg as the figure most thrown around when I was considering a Toureg 2. I'm sure an I4 would be more efficient (less moving parts, parasitic loss, less friction surface area), but I'm sure they'll have to put up with some unique challenges to a large 4 banger such as balance shafts (these are never good) and NVH.

@ Dave again
You may be surprised to hear that the average 40' transit bus only has 280 - 300 HP from a Cummins ISL (We spec the 280 motor for fuel economy, and another note that those things make nearly 1000 ft-lbs of torque). Those vehicles have a GVW over 40,000 lbs, which is far beyond any half ton. Though you won't win any drag races, you will have sufficient power to do everything a half ton should be rated to do as long as you're over 200hp, including hauling an 11,000 lbs trailer.


The truck should be able to move 11,000lbs no problem with ~200hp.....that's not the issue. The issue is what it will be RATED to tow. Remember that we now have an SAE towing standard that manufacturers have elected to follow. If this engine can't meet the loaded acceleration requirements for 11,000lbs, it won't be rated to tow 11,000lbs. Simple as that.

Based on the HP and TQ numbers, this engine is going to be a dog compared to modern V8's and even some modern V6's. That might end up being a problem when it comes time for the manufacturer to attach a rating to the trucks towing ability. It might be able to handle more than it is rated for just fine, but still ends up getting an extremely low rating just because it's not a speed-demon of an engine.

The question then becomes....will people pay more for an engine that's rated to tow significantly less than max just because it gets better fuel economy? That's tough in a market of truck buyers who like to "have their cake and eat it too."

I think a 2.8L diesel is a great idea!....In a compact. Not saying that either Nissan or Cummins is making a mistake...I mean at least they are experiminting.

But honestly I think this engine would be much better suited in a smaller lighter compact truck. 220hp and 380lb/ft of torque will be ''percived'' as less than adequte by the public in todays 1/2 ton trucks. 380lb/ft of torque should be fine for almost any 1/2 ton truck owner. But the problum is that the public has gotten so used to seeing 1/2 ton trucks that make between 300hp and 400hp even ''Fords 3.7L base V6 makes over 300hp these days'' so the 220hp this engine puts out will seem pathtic compared to any modern V8 or even V6's output for that matter. Another thing is the fact that its a 4cyl engine. In any fullsize vehicle most of the general public wants a V8...Will accept a V6...But its pretty much unheard of to have a 4cyl in a full size truck diesel or not.

Under the hypothetical that this engine DOES come to production I think it would be better suited to the Nissan Frontier. If Cummins and Nissan really beleive that they can pass the CARB standerds with this engine and still get 34 highway MPG out a fullsize Nissan Titan...Imagine how much better it would be with the 1000lb lighter Nissan Frontier? 40mpg? 45mpg? It seems really far fetched, and I am a ''I'll beleive it when I see it kind of guy'' Back when everyone was expecting the Ecoboost to get a 30mpg highway rating I said the excat same thing and what the Ecoboost wound up getting was the early 20's highway rating I expected it to get. Now don't get me wrong, I'm a die Ford guy and I think Fords Ecoboost is a cool engine...But I knew all along it wasn't going to get 30mpg in the F-150 as it struggles to get mid 20's highway in the smaller lighter Ford Flex.

So as I've already said, I think this engine is better suited to a smaller truck. The 4.4L, 4.5L and 5.0L Diesels that Ford/GM and Ram supposedly have sitting on the bench waiting to play, would probably be a better displacement for a 1/2 ton truck.

@Nate M the Nissan Navara is 4,500lb with its 3 Litre diesel and that is about right. A 4.5 -5.0 diesel would be great for a full size 1/2 ton., 550-600lbs of torque. It would do a lot of things a HD does now.

The small diesel will not be for everybody but 380lb/ft at 1800 is a strong engine. If it's getting 25mpg+ combined along with Cummins durability I don't see why anybody would have a problem with it being an option. If anything it'll help keep the 400HP+ V8's around for a longer time.

I wouldn't be surprised if the SAE tow std is adapted to meet goverment fuel economy standards since we'll see fewer and fewer high hp/tq pickups and vehicles in the future.

Since the 28 mpg combined figure was used in association with 2016 CAFE requirements, it appears that the mileage estimates may be the EPA UNADJUSTED values. CAFE is based on the unadjusted "combined" value.

For example, the Touareg 2 has unadjusted mileage values of 23.4 mpg "city", 40.7 mpg "highway", and 28.9 mpg "combined", but gets 19/28/22 "adjusted" mileage (EPA "5-cycle"). It appears that the Titan with this engine may get roughly the same mileage as the Touareg 2, so the actual mileage values (EPA "5-cycle") that appear on the sticker for this truck may be more like the Touareg 2 - 19 mpg "city", 28 mpg "highway", 22 mpg "combined".

Maybe Mike Levine can shed more light on this?

Lets put this in perspetive. Go back to 1999 and the era of well loved 5.9 Cummins in Dogde 3/4 and 1 tons.


5.9L V8 - 245hp@4000 -- 335@3200
5.9L I6- 215hp@2700 -- 420@1600
5.9L I6 - 235hp@2700 -- 460@1400
8.0L V10- 310hp@4000 -- 450@ 2800

So the towing kings of the day had 215-235 hp. These were enough for what? 13k goosnecks? With 6speed I bet 220/380 will be enough to cover most needs for a 1/2 ton.

This engine should be in a mid-sized truck like the Tacoma, not the full size Titan. Which it fails to sell more than 30k Titans a year.


Looking at the pictures, this appears to be a physically very tall engine. I'm guessing it has a pretty long stroke, which contributes to a high deck height. Because of this, I'm thinking it might not fit in a mid-size truck.

"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."

You sure about these numbers Jason? My 2006 Ford 5.4 makes 305hp/285tq. I think 220/380 @ 30+ MPG would suit me just fine.

@ PowerCell
'07 power rating for a 5.4
300 HP @ 5000 RPM
365 TQ @ 3750

The '06 is rated at 300 hp and 365 torque. In 09 it was increased to 310 hp. 5000 lb tow ratings will suit some just ine. Others it won't.

I'll believe 30+ mpg when we see it in a real truck. I hope it does get 30+ mpg. But as Dave pointed out, Mahindra was supposed to get 30+ and came back at 19/21.

@ Jason
yea it seems truck manufacturers are stuck at 15/21 MPGs
don't get me wrong i would be happy to see this thing succeed
but there is just to much BS that goes wrong with diesels anymore

220/380 makes no sense at 21 mpg, but at 30 mpg hwy? Different story.

I would happy with 2 choices.
220/380 at 30mpg hwy for standard work truck 1/2 ton
250/420 at 27mpg hwy for max towing 1/2 ton
250/420 at 25 mpg why for base 3/4 ton (2500lbs payload)

We don't all need 800ftlbs or need to tow 15k trailers

WOW, I'm sure glad for 397 hp 765 ft-lbs Duramaxs!

Some of you are comparing gas hp/torque to diesel numbers. Not applicable as diesels make the power at far lower rpm. Traditionally diesels are not high hp, but high torque. Yes the 5.6L Nissan V8 is making 380 torque, but it is doing it at 4,000 plus rpm. More rpm, more fuel burned. FWIW I own a 2005 Titan. Some of you are posting outright lies about the Titan. Nissan said from day one the Titan wasn't introduced to outsell Ford or GM. It was marketed to get a piece of the truck market. Which they did. They had no desire to compete for sales dominance. Nissan is a fairly small manufacturer of autos and trucks. As a manufacturer its sales trail the Big 3, Honda and Toyota. Why would their truck sales be any different?

The reason fords 5.4 is a dog is because it was fords top engine which competed against other engines producing nearly 400 hp. It's not that it wasn't enough it was just less than what everyone else had. As far as the hp and tq ratings of this diesel, its definitely enough. My 93 cummins has similar tq and less than half the hp of my 04 hemi durango. Guess which one tows better. Gas hp/tq is not the same as diesel hp/tq when it comes to having enough to get the job done.

Many are changing their tunes from when they were first calling it "perfect."

First, it was perfect. Now it is "enough to get the job done, acceptable, suit me fine (ie for commuting and light load). "

Now it is barely adequate and meeting only minimal requirements.

30+ would be a pretty big jump. I bet it will get closer to 27.

This is great news. Its not so much the cost, but the public stigma on diesels due to "noise" and they're "dirty". But this is something that was true of diesels from years ago. Modern diesels are a lot different... look at VW for a perfect example, and why you can find Civics, accords, corollas, camerys, and others who don't offer diesels here but do in Europe. If you want to check it out yourself just hit up their websites... WWW.Honda.co.uk WWW.Toyota.co.uk WWW.Nissan.co.uk
(I'm guessing at the euro address for Nissan)


Jordan L - good points

why is DOE contributing $15 million when GM, Ford and Chrysler already have developed diesels suitable for 1/2 ton pickups but have not released the engines (GM was a few months away from beginning production in Tonawanda, N.Y. before bankruptcy) At least require Cummins to return the $15 million if the engine is not produced commercially in 3 years.... remember the $1 Billion given to the big 3 to develop a 60 mpg diesel when Gore was V.P.; the money was spent, an engine developed and never produced!

For just a few thousand dollars more, 1/2-ton diesel versus a 3/4-ton diesel (merely guessing on price differences),, I would rather have 400 horsepower and 800 lb-ft. of torque. Only available in the Ford Super Duty, with the Scorpion 6.7L, of course.

@Jordan L, they offer the 3 Litre Mercedes diesel for the Chrysler 300c. Same question: guess which tows more? the 425hp Hemi or the 3 Litre diesel.

If Nissan is a joke in the 1/2 ton world (which I somewhat agree with) it comes from a lack of updates. Upon it's release, it was a real contender in every category except maybe sales. For just jumping into the 1/2 ton market, Nissan hit a home run with that truck a few years ago. If they keep their head in the game and are willing to spend the time and money in development, they'll build one hell of a reputation for their trucks.

I dont know why are all saying it is way underpowered. My 97 Dodge Ram was rated at 180 hp and 440 pounds of torg. It can pull pretty much anything i need to. Now before anyone says it,,, YES the 5.9 cummins is way under rated and can very easily be modded to get much more power. Thats true, but I am saying in 2003 I hauled RV campers from Indianna to Alberta and never had a problem with any of them.

Way to go Nissan,,, if you do produce this truck, it will SELL

I thought that the next gen Titan was gonna be a re-badged Dodge Ram anyway.

I see the future. Right on.

LOL @Jason. You guys like to blame the President and the CAFE standards for high gas. It's Chinese, Indian, and Opec-nation demand as well as the looming reality of Peak Oil. If you look at exploration and discovery totals since 1980, you'll see what awaits us.

Drill all you want: the new finds in the deep ocean won't bring us another Saudi Arabia. The days of cheap oil are history.

We'd better get used to smaller and thriftier engines. We'll enter an era when, thank God, trucks are for work. They won't be toys, and we won't need big displacements and lots of horsepower to get work done.

We complain about fuel costs, but do little to change out habits.

I've been playing around with some hypermiling techniques and I've gained a few mpg out of it around town.(13.8 normal driving to 16.7 hypermiling). That is based on my trip computer, but the trend is an improvement. Last fill up i was around the 13.5 mpg mark all the time. I've averaged 12 - 14 since I bought my truck. I'm not including winter as that really sucked. Now i'm around the 16.7 mark most of the time.
I'll have a better idea as to the overall gains next fuel fill up.

The biggest thing that kills trying the hypermiling techniques is other traffic. I try not to be slow and smooth with heavy traffic. it just pisses everyone off.

I have been attempting to use the hypermiling techniques, also. It is difficult though, with the amount of traffic lights and other drivers on the road. I need to move to a rural area?

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