Diesel Truck Winterization Tips for Denver fleets

The winter months will always come with some huge negative externalities for commercial vehicle fleet operators. Nevertheless, most of these negatives can be mitigated, or avoided, by proactive maintenance.

The most obvious negative impact of winter weather is on safety. Slicker roads, poor visibility, and increased driver fatigue all result from the snowstorms and freezing temperatures associated with winter. However, there’s a lot that can be done to maximize a driver’s chance of staying safe on the road.

Tires are the most important thing to check out.

Tires are the only point of contact between the vehicle and the road. As such, not only are they the single component most responsible for a vehicle’s traction on the road surface, but they can also provide valuable indication of whether a vehicle’s other components need maintenance.

Tires should be well maintained year-round, but they become even more important in winter when vehicles have to deal with inclement weather. Uneven tread wear not only presents a danger on the road but can also be the telltale sign of maintenance that has been neglected elsewhere. Uneven wear on treads could point to problems with alignment, or even larger problems with wheel-ends.

Speaking of wheel-ends, winter contributes to the ease of their visual inspection. In summertime, wheel-end temperature needs to be measured with a thermometer. In the colder winter climate, though, a wheel-end that is overheating will give off a telltale excess of steam. Overheated wheel-ends indicate a lack of lubrication or improper clearances and should be immediately serviced if spotted.  

Apart from safety concerns winter also impacts a vehicle fleet’s performance. Cooler ambient temperatures cause tires to lose pressure, increasing their rolling resistance and decreasing the vehicle’s MPG. Increased aerodynamic drag associated with colder temperatures represents a further loss of fleet efficiency.

A certain loss of fleet efficiency is inevitable during winter, but that loss will only be compounded if you go into the season with improperly maintained vehicles. Preparation and prevention are key to saving time and money over the winter months. Accordingly, vehicles should go into winter at their best.

Comprehensive preventative maintenance at the end of autumn will save money by the beginning of spring.

Tires need to be rotated, wheel-ends inspected, and the fuel system purged of water. Water turns to ice when it’s freezing cold outside. Ice in the fuel system dents efficiency, but it’s easy to fortify the vulnerable parts of the system.

The filters and water separators are the parts of a fuel system most likely to accumulate water ice. Filters should be cleaned and water separators should be drained before the first cold-snap of the season. Fuel and coolant lines are especially vulnerable to cracking in freezing temperatures, and they should be patched or replaced if worn.

Maybe the most overlooked aspect of winter weather is its effect on diesel fuel itself.

 Diesel reacts poorly to colder temperatures. 75% of diesel fuel is comprised of saturated hydrocarbons called paraffins. There’s a lot of complicated chemistry behind it, but it’s easiest to think of these paraffins as kind of like a wax candle.

A candle is solid at room temperature, but its wax melts into a liquid when you get it hot.  Diesel fuel is essentially like candle wax, but it’s liquid at room temperature and it explodes when you get it hot.

Just like hot liquid candle wax starts to turn into a gel when it cools, diesel fuel is known to “gel up” when ambient temperatures get colder than about 15 degrees Fahrenheit. At this temperature, the “wax” in the diesel becomes too solid to flow through fuel systems, rendering a diesel engine inoperative.

There are a few ways to stop diesel from “gelling up.” The easiest is to keep your vehicles warm. Whenever possible diesel vehicles should be stored in heated garages in the winter months to ensure that they’ll start and run when they’re needed.

Another method is to apply fuel additives to the diesel. There’s a lot more complicated chemistry here, but essentially these additives lower the temperature at which diesel starts to turn into a solid. Traditionally, the additive of choice has been kerosene. But kerosene is expensive, and some cheaper alternatives have been introduced.

Whether it’s roads, drivers, tires, fuel systems, or the fuel itself, winter presents challenges for every commercial fleet. But with good planning and proactive maintenance, your vehicles can weather this difficult season.