Q: I am heading to the snow this weekend with my BMW X3 diesel. Do I need Alpine Diesel? And, if so, what is Alpine Diesel?
A: Regular diesel sold across Australia is rated to work across a variety of vehicles and operating temperatures. At lower temperatures, diesel reaches a 'cloud point' where wax begins to form and causes the fuel to become thicker.
The thickening effect can cause the fuel to clog filters and affect the vehicle's performance — in some instances, it will prevent the vehicle from starting all together.
Australian Standard AS 3570-1998 specifies the maximum cloud point limits for diesel across Australia during certain months. The lowest limits in Australia exist in Tasmania, where diesel is allowed to reach its cloud point at temperatures lower than -3 degrees Celsius in June.
Alpine Diesel is a diesel fuel blend that is manufactured with a cloud point that sits 4 degrees Celsius below the regular diesel cloud point — thus increasing the operating range before wax development to -7 degrees Celsius in the Tasmanian example from above.
If you are planning to drive or store your diesel vehicle in areas where the temperatures are likely to exceed that of the allowable cloud point, you need to invest in Alpine Diesel.
Some areas also sell Highland Diesel, which is similar to Alpine Diesel, except it increases the operating cloud point range by 2 degrees Celsius instead.
Drivers travelling into even colder climates can use an additive in addition to Alpine Diesel to further increase operating range.
Vehicles that use unleaded fuel won't need to use an 'alpine' fuel or additives. Unleaded doesn't develop wax in the way diesel does and its freezing point is beyond -30 degrees Celsius.
We hope that helps, Tom. Enjoy your time at the snow!