While a Mack Super-Liner with a Detroit Diesel Silver ‘92 powerplant is not your everyday truck and engine combination, it is one which has served Marcus Prillwitz well.
His #31 Hi-Tec Oils Racing truck has been a regular fixture on the Australian truck racing scene for over a decade.
At the final round of the 2025 Super Truck Racing Series, held at the Winton Raceway in Victoria, Marcus had the Mack wound up in search of some sharp lap times and race results.
It would be fair to say that the Mack is not a full-blown pedigree Bulldog, with the truck having been built out of a number of different components into a race unit.
In between a busy weekend of qualifying and racing Marcus gave a background to both the Mack and the overall truck racing scene.
“I have been racing it for 12 years; it is the only truck I have ever raced and it’s somewhat of a bitser – it was built out of spare parts,” Marcus said.
“It has Mack CH chassis rails and the Super-Liner cab was an offset left-hand drive cab off a Fijian garbage truck.
“I gutted it and got a Super-Liner bonnet made up for it. It has a DAF rear axle and a Meritor front axle which was originally in a Freightliner Argosy – and of course to see a Detroit in a Mack is pretty rare in Australia.”
Under the large square bonnet the Detroit powers the Mack down the track and having had many years’ experience with the Silver ‘92 derivative, it was an obvious choice for a powerplant when Marcus was piecing the Mack together.
“I owned a company called Victorian Diesel Servies, and I used to work on a lot of touring coaches back in the day when the Detroit Silver ‘92 was the most common engine.
“This 8-92 has a twin turbo and it’s also a bitser of all the go-fast Detroit stuff – that same motor in a boat would put out about 750-800 horsepower so that’s not a bad starting point. Once you source some bigger injectors and so forth, so we are up around the 1200-1300 horsepower mark.”
Originally the Detroit was coupled up to a Roadranger gearbox, but Marcus made the switch to an automated driveline a couple of years ago.
Running an auto ‘box puts the Mack on an equal footing with most other competitors and Marcus reckoned that the move had been a smart one.
“Over the years we have broken three crankshafts in the motor and we have just put the fourth one in it.
“I would like to think it was due to the Roadranger in it, there is a lot of shock going through it when you are racing with the Roadranger behind it compared with the auto.
“I don’t think it’s made it any faster, but it is certainly easier to drive! It was really good fun with the Roadranger, I miss that but on the flip side it’s probably a second or two quicker – there is a lot less to think about as you’re going around the track.”
The truck racing fraternity is a close, tight knit community with teams. While competitive out on the track, all help each other out once the racing stops, and Marcus reckons it’s a good way to go racing.
“My only other motorsport experience was I crewed on a sprint car and the guys in the pits on the teams wouldn’t talk to each other as it was so competitive,” he said.
“Super Trucks is definitely not like that, if it was, I wouldn’t be doing it. With [fellow competitor] Frank Tringali’s International, we built our motors together, that’s the sort of camaraderie we all have. When we are here at the track for the weekend everyone is all happy to help, it’s a great family environment and everyone gets along – the social aspect is priceless.”
With new trucks taking to the track in 2025, and the addition of new circuits such as Queensland’s Morgan Park to the calendar, the Super Truck racing scene is in a good place.
For long-term competitors such as Marcus, the Super Truck Racing Series is still a good thing to be a part of.
“Going to Morgan Park for the first time last year was really good, it is a great circuit to drive with the uphill and downhill aspects, and I really did enjoy that.
“The racing fraternity is opening its arms up to the truck racing again – we are under new management, so to speak, with a new committee and some fresh ideas.
“In the past we were probably a bit notorious for a bit of ‘crash and bash’ but that has been tidied up a bit and that’s good for the racing and also for our sponsors and exposure. Crashing and bashing about is not race craft, and there’s no fun trying to load your racetrack back up with a forklift.
“A good meeting is one where you can drive it back up onto the trailer – and a great one is when you go home with a trophy also. The series is starting to become recognised again and it’s a great time to become involved with it.”
The first round kicks off at Mallala in South Australia across the Anzac Day weekend in April, with Morgan Park and Winton again locked in for rounds in 2026.
For more information about the 2026 championship, check out the website at truckracing.com.au.
• Big Rigs would also like to acknowledge the recent passing of long-time truck racing competitor Barry Butwell, who passed away in January.
Often racing at the front of the pack, Barry took out the championship in 2023, earning the right to display the #1 on the doors of the Butwell Racing Team’s red Mack Super-Liner.
Big Rigs extends its condolences to all Barry’s family and friends in the race paddock.