Dual fuel Scania R380 long-haulage trucks

We have 3 x 140L type 2 CNG cylinders installed behind the cabin in steel frame. Total weight with CNG full load is around 650kg, storage volume 100nm3 with 200 bar working pressure. So max mileage we got is 400km, which is not enough to run full distance between Petersburg and Tver (500km) in dual-fuel regime. Truck goes in diesel regime last 100km, but in week time we increase cylinders number up to 5, getting 600-700km mileage and full CNG coverage through all distance.

We have installed our quite standard Triol dual-fuel system with PPS (gas pedal) emulation ( description ). One new feature: detonation monitoring system installed for calibration period and removed later.

Please see pictures below:

2 tests were conducted, first with max container (10 concrete block 1 ton each at the bottom plus used tires up to the top = 20-24 tons load full weight) and second test without load, for standard full-load – coming back empty long haul cycle.

Test conditionsScania run round trip Krivko village – Petersburg 130km including hilly part 20km. All tests were performed with the same driver, at first diesel-only round, then dual-fuel round.
Diesel fuel consumption was measured using calibrated pump. Before the round vehicle was fueled in full, then after the round it was fueled in full again and liters number became diesel consumption per round trip. CNG consumption was measured by pressure gauge and calculations using cylinders volume and temperature.

Substitution rate, power and torque Diesel test No 1, full load: 45L per 130km
Dual-fuel test No 1, full load: 130 km consumption: 17L diesel + 31nm3 CNG, 62% substitution coefficient
Diesel test No 2, no load: 37L per 130km
Dual-fuel test No 2, no load: 130 km consumption: 15L diesel + 28nm3 CNG, 60% substitution coefficient
Driver reported no power losses or uneven torque, vehicle moved even and steady.

Tractor truck annual mileage is 120 000 km average, assume 35L/100km average diesel consumption, 1 USD per liter diesel fuel price, so annual diesel fuel cost is 120.000/100*35*1$= 42 000 USD
Let us assume substitution coefficient is 60%, so annual diesel cost becomes 25 200 USD. Annual CNG consumption is (120 000/100*35)*0,4*1,05 = 17 640 nm3, with a price of CNG 0,5USD per 1nm3 annual CNG cost is 8 820 USD. Total annual fuel expenses is 25 200 + 8 820 = 34 020 USD.
Annual saving is 42 000 – 34 020 -= 7 980 USD.
Total capital expenses:
• Our equipment EXW price is 2000 USD,
• Equipment transportation and customs (estimation) 500USD
• 1000USD our equipment installation price (can be done by your labor force)
• 5 CNG cylinders x 140L x 4 USD per liter = 2800 USD,
• cylinders frame 500USD
• cylinders and frame installation 1000 USD (can be done by you also)
So total cost is 7800USD including all expenses necessary.
So as you can see payback period is 1 year roughly.
You should take into account our equipment lifetime is 20 years so in following 19 years you earn
7 980 x 19 = 151 620 USD
Would you decide to sell your truck and buy new, so our equipment is easy to remove (6 hours max time) and install to the new vehicle.