The Shell Starship Initiative is an experiment on wheels. It focuses on energy-efficient truck design using technologies currently available while simultaneously testing lubricants and tech that are near-to-market. I was once a truck driver and I found the work Shell is doing here to be fascinating.
Shell is on its third rendition of the Starship truck since the Starship Initiative began in 2018. The first two versions of the North American design of this truck were based on diesel engines. The new Starship 3.0 has a natural gas engine instead – one that Cummins brought to market in 2024 and that is made specifically for heavy-duty trucking and machines.
The engine itself is a huge step forward in engineering, having defeated the main drawbacks of natural gas as a fuel source for trucking – namely fuel efficiency and power delivery. Cummins’ new X15N engine is a large-bore design that operates similarly to a diesel engine in that it achieves similar power outputs, but does so with more efficiency and far fewer emissions. The major upside to natural gas is its lower emissions (meaning fewer power-sapping emissions scrubbing systems) versus other options. It’s also more versatile, with the Starship 3.0 being capable of operating on compressed or liquefied natural gas, including renewable natural gas. The latter (RNG) being a key point here.
With previous models of the Starship, Shell has improved and tested lubricants made for diesel engines and drivetrains. That has led to great leaps in efficiency gains. For example, two decades ago, 20-weight oil was a norm in heavy-duty trucking. Since then, thanks in large part to Shell’s experimentation and testing, that has reduced to 10W and is getting close to averaging at 5W as it sees more and more adoption in the industry.
Each step of 5 in oil weight reduction means a 2-3 % improvement in efficiency. Shell says they are very close to bringing a 0W engine oil for heavy-duty applications to market. Similarly, advances in the lubricants used for transmissions, axles, etc. have also made big strides.
I got first-hand with the oddly futuristic-appearing Starship 3.0 to talk with Shell about this experimental rig and see what it can do in reality versus on paper. The truck is fully custom, but built using currently available technologies. I was most interested in spending time with the two brothers, both professional career truck drivers, about what they thought of it. From a real-world viewpoint.
The Shell Starship is a big leap forward from the big rigs I drove 20-plus years ago. Back then, diesel was king and rolling into 7 miles per gallon (33.6 L/100km) was a feat. Anecdotally, my average freight ton miles per gallon was in the 50s. Largely because of the heavy truck (Kenworth T800W with exterior pipes), heavy trailer (refrigerated box on aluminum frame), and low-rent transmission (10-speed Alison) setup I had. That truck is long gone as an option today, in terms of its inefficiency. Today’s versions of that truck are 10 mpg (23.5 L/100km) or better without adding any aerodynamics (trailer tails, skirts, cab wings, etc.), which improve that even more.
The new Cummins engine is about 500 lb (227 kg) lighter than its diesel equivalent, adding to the potential freight-carrying weight the Starship 3.0 can haul. Other lightweighting adds to that, giving the Starship 3.0 a ton-miles per gallon efficiency of 183. That’s a big leap compared to the industry average of 72. It’s important to realize that although many think of mpg as the benchmark, freight-ton mpg is much more telling. It’s the reason the average big rig on the highway gets better fuel efficiency than a Prius, despite its mpg being in single digits. It’s also a reason that battery-electric trucks struggle to find market share. The larger the battery, the less cargo that can be carried, and the lower the freight-ton per mile. Tesla, for example, has still not released tare weight and other important figures for the long-awaited (and delayed) Semi.
For Shell, though, the natural gas engine posed some challenges. Lubricants for the higher-heat engine had to be developed. Derived from gasoline lubricants, Shell formulated the Starship’s options specifically for the engine. Bench testing using prototypes of Cummins’ new engine got the blend ready to market and now testing in the Starship 3.0 is perfecting them further.
“The Starship is a lab on wheels,” said Heather Duffey, global integrated communications manager for Shell Commercial Road Transport Lubricants. “Every time this truck drives across the street or across the country [it’s done both many times], we get more data.” The truck is currently using Shell Rotella NG Plus SAE 5W-30 FA-4 synthetic engine oil, formulated specifically for the higher heat an NG-burning engine produces as compared to diesel. The truck’s Eaton-made automatic transmission uses Shell Spirax S6 GME 40.
Duffey pointed out the obvious when we talked about the Starship 3.0 and why it uses natural gas instead of, for example, a hybrid or fuel cell setup. “Fleets are not going to run out and buy something new. They want what they know works.”
Everything on the Starship that isn’t the cab’s bodywork or experimental lubricant is off-the-shelf. Shell considered hydrogen as an option, but the infrastructure isn’t there. Instead, with Cummins releasing a natural gas engine, Duffey said Shell saw “something that fleets can adopt now. There are fueling options nationwide, already in place.”
The drivers of the Starship, brothers Brian and Eric Rector, have also given a lot of input into the Starship’s design and changes. Career truckers, they own their own trucking business and drive the Starship for Shell as needed. They both like the natural gas engine and have completed several long-distance drives in the Starship in all three of its iterations. The 3.0 model, however, offered a chance to compare powertrains.
“It drives almost exactly like the diesel one did,” Brian told me when asked about a comparison. “It’s a little [quicker] on the uptake, maybe, but other than how we fuel it, it’s the same.”
Eric told me about an 840-mile (1,350-km) loop throughout California in which the Starship 3.0 was loaded with engine oil. The performance data and input from the drivers helped shape the ergonomics of the setup and had the side benefit of creating an ad-hoc map of NG fueling stations around the state.
“We were especially surprised at how many renewable gas options there were that weren’t marked as such on our existing maps,” he said. “We also saw how things changed as the loads changed during our drive,” he noted. How a truck drives changes by the weight it’s carrying. “The Starship is no different. But the engine output was smooth no matter what we had on board. That was a surprise.”
Most drivers, like myself, would assume that the higher-burning NG would be “jumpier” by comparison. Once in the truck, I saw that Eric told me no lies. The engine and transmission work smoothly together.
The data collected during the brothers’ drives has been instrumental in Shell’s improvement of its products for the sector. The Starship is out doing the day-to-day work that gets little attention, but that makes all the difference. Offering two and a half times the efficiency using things that are almost all available right now, off the shelf, is a big deal. And it’s only getting better.
Source: Shell Starship Initiative
