Was the Cummins ISF2.8/R2.8 engine underestimated?

[cRiPpLe_rOoStEr]

I guess some folks here may remember the development of the Cummins ISF2.8 engine project was partially funded by DARPA, using Nissan trucks as testbeds, despite being more successful in overseas markets such as China, and even Russia and Brazil.


Sure the ISF2.8 being fitted to this might've caused it to become somewhat underappreciated, while some models one or two classes below could'be been better served by such engine.

Maybe, instead of the F-4000 which was roughly a Brazilian equivalent to the DRW F-350, could be suitable for the F-150, even if it wouldn't match the performance of the V6 turbodiesel which in the F-150 is now AFAIK available only for a few overseas markets such as the Philippines.

And even though Ford and GM took different approaches regarding the 2.7L turbocharged gassers, with the F-150 being available with a V6 while the Silverado resorted to a 4-cyl, maybe it wouldn't be so pointless for US-spec trucks to eventually feature a 4-cyl turbodiesel. It did surprise me GM never even tried to fit the 2.8L 4-cyl Duramax into the current generation of the Silverado instead of the 3.0L straight-6 Duramax which ends up being more expensive to manufacture. Considering most buyers of the turbodiesel go for the fuel-economy, while anyone looking for the bragging rights prefer a V8 gasser anyway, maybe both the Cummins ISF2.8 and the 4-cyl Duramax could still be reasonable powerplants for trucks within this class.



And since the ISF2.8 might be ultimately the most successful derivative of that project which resulted in the failed ISV5.0 V8, originally intended to be a 5.6L V8 which would have a 4.2L V6 counterpart, intended to replace both the 5.9L straight-6 and the 3.9L straight-4 B-series engines which ultimately were replaced by 6.7L and 4.5L versions of the B-series instead, maybe if could make sense as an option for the Ram 1500, considering how featuring a Cummins engine in the 2500 and larger models is widely credited to the success of Ram. Maybe with a less conservative tune than what I used to see more often before Euro-6 was implemented in my country.

[Piotrsko]

With cummins, you have this fanatical name following derived from long haul truckers that is concerned with reliability after over boosting to get enough power to move heavy stuff. My 7.3 navistar would self destruct at the boost a cummins would survive, or so the street saying indicate. I make 230 hp, the cummins can do 400+

Might be a better answer from @JSH

[JSH]

Cummins does have a rock solid reputation and following in the commercial market. A ISB 6.7 paired with an Allison automatic dominates the medium duty segment. Cummins is so popular that other manufacturers are dropping out of the market. For example Daimler Truck will stop producing their medium duty engines in 2026 and will just buy from Cummins. There was no point in doing the development to meet EPA 2027 and Euro 7 which come into effect for 2027. Those commercial buyers are also buying cummins with a lot less power than the guys buying a Ram 3500. A ISB 6.7 powering a school bus, RV, utility truck is making 200 - 300 hp and 520 - 800 lb-ft. while the ISB 6.7 is a Ram 3500 is turning out 420 hp / 1075 lb-ft.

Which brings us to why diesel is almost dead in the USA - economics and emissions. Diesel fuel has been more expensive than regular gasoline in the USA since 2007 when we switched to ULSD to allow for particulate filters. On average 18% more per gallon. So yes, diesels get better fuel economy but the economics are about a wash when you pay more for the fuel. Add in the extra cost to buy the engine and the extra cost for maintenance and why would someone that cares about cost / mile buy a diesel? Also why buy a truck that goes into limp mode 500 miles after the smallest emission fault?

Then we talk about emissions. EPA 2027 drops allowed NOx by 75% and PM by 50%. It also more than doubles the "useful life" were the engine has to meet emission standards and extends the mandatory warranty for emission equipment. EPA 2027 is expect to raise the cost of a diesel by $10,000 - $15,000. So a diesel that isn't economical today outside of a few applications becomes even less economical in a few years. Gas engines are taking over the medium duty segment today and that will continue.

EPA 2027 will also be a problem for DI Turbo gas engines as will the light duty version Tier 4. Hitting emissions with a DI turbo gas engine will require particulate filters just like for a diesel. (They ecoboost Maverick gets one in 2025) I doubt gas engine buyers while embrace them any more than diesel owners have. They certainly aren't that popular in Europe where they started being used back in 2014. Particulate filters don't like stop and go traffic.

Personally I expect to see hybrids take over the ICE segment. A low compression NA gas engine paired with an electric motor can produce the power required without the emissions headache that comes with turbos and get great fuel economy. It will be interesting see Ford's solution for the Super Duties. They have already said it will be electrified. I'm wondering if they go all in a make the 7.3L Godzilla a hybrid or use one of the smaller V8s - or both. Or do they go RAM's route and do a serial hybrid like the ramcharger?

Jason

[cRiPpLe_rOoStEr]

Originally Posted by JSH

Cummins is so popular that other manufacturers are dropping out of the market.

It was quite shocking to me figuring out even Isuzu is now outsourcing some engines from Cummins for its US-spec F-Series trucks.

Diesel fuel has been more expensive than regular gasoline in the USA since 2007 when we switched to ULSD to allow for particulate filters. On average 18% more per gallon. So yes, diesels get better fuel economy but the economics are about a wash when you pay more for the fuel. Add in the extra cost to buy the engine and the extra cost for maintenance and why would someone that cares about cost / mile buy a diesel?

In Brazil, even though Diesel fuel was occasionally more expensive than ethanol and CNG, only from 2022 on it became more expensive than regular gasoline. But for heavy-duty engines it's still basically impossible to get rid of, even though I have already seen more dedicated-CNG big rigs in recent years, not to mention some converted to run on Diesel fuel and CNG at the same time.

Hitting emissions with a DI turbo gas engine will require particulate filters just like for a diesel. (They ecoboost Maverick gets one in 2025) I doubt gas engine buyers while embrace them any more than diesel owners have.

I used to be more favorable to downsizing until around 2018, when I found out about particulate filters on DI turbocharged gassers...

[JSH]

Originally Posted by cRiPpLe_rOoStEr

In Brazil, even though Diesel fuel was occasionally more expensive than ethanol and CNG, only from 2022 on it became more expensive than regular gasoline. But for heavy-duty engines it's still basically impossible to get rid of, even though I have already seen more dedicated-CNG big rigs in recent years, not to mention some converted to run on Diesel fuel and CNG at the same time.

That is because Brazil's P8 emission standard (similar to Euro VI) started in 2022 and Brazil had to reduce the sulfur in diesel to keep from killing the aftertreatments. When countries switch to ultra-law sulfur diesel the price goes up. ULSD = 15 ppm Sulfur or less

Brazil's emission standards are roughly 10 years behind Europe and the USA.

[cRiPpLe_rOoStEr]

Originally Posted by JSH

When countries switch to ultra-law sulfur diesel the price goes up.

There are still some fuel stations where S-500 Diesel can be found, yet S-10 ULSD has been more widely available locally. I remember when S-50 became standard in 2012 (it was a Premium fuel prior to that), yet S-10 in 2013 started to become mainstream. War on Ukraine was the reason for Diesel fuel prices to skyrocket in 2022 more than any emissions-related issue.

[Piotrsko]

As long as I can buy diesel, im good. Making and transporting bio would be a pain, but my superduty is only 1/2 life at 24 years.

@JSH: what are the industry plans for diesel power going away?

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Making and transporting bio would be a pain, but my superduty is only 1/2 life at 24 years.

At least some previous-generation Diesels were easier to adapt to run not only on biodiesel, but even on straight vegetable oil avoiding the need to homebrew biodiesel

But anyway, IIRC the Cummins ISF2.8 when fitted to the Brazilian Ford F-350 and F-4000 was already B20-capable.

[Piotrsko]

It's been demonstrated to run on 100% veggie oil, but only on warm day's maybe 15 years ago. Either a viscosity reducer additive or a better fuel heat method is needed. But at $5.00 @ gallon at wallyworld, it is only slightly cheaper than diesel here in Reno right now.

So much simpler to make it biodiesel and deal with the water and glycerine byproducts and buying it in bulk might make it cheaper

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Either a viscosity reducer additive

Turpentine gets the job done.

Back on topic: there is no Euro-6 version of the ISF2.8 engine available here in Brazil, so Cummins is placing a higher bet on the ISF3.8 instead. Well, maybe the ISF3.8 due to its higher displacement could still be better suited even to an American, if a 4-cyl turbodiesel on a half-ton would ever be taken seriously there...