It goes without saying that HVAC work shifts with the seasons — you’re not as likely to get a call for a/c repair in the middle of December. But did you know that the same mentality can apply to your company vehicles?

Making sure your trucks are protected from extreme heat and extreme cold can be the difference between fast response times for your customers and massive unplanned downtime that could have been addressed with simple preventive maintenance tasks.

James Shelton is the technical field support manager for Jiffy Lube International, and as an ASE Master-Certified technician, he understands vehicles inside and out. Here are a few tips he recommends that HVAC fleets follow to keep their trucks ready to go year-round:

1. Focus on fluid levels, no matter the season.

Your vehicles’ fluids will react differently depending on the weather, and knowing those differences will ensure that a truck will run the way it’s intended to.

“We're probably very aware that as things get colder, they get thicker,” Shelton said. “You've heard the saying ‘thick as molasses in January.’ Think of your motor oil the same way.”

Other fluids are likely to freeze in the winter without proper freeze protectant, especially if you live in an area where temperatures regularly drop below freezing.

For warmer climates, Shelton recommends verifying the quality of the oils you use to ensure that they are right for your vehicles. Each vehicle’s owners’ manual will give OEM guidelines that you should always follow to the letter.

“We're always going to use the manufacturer's recommendation, because a lot of people think, ‘Oh, hotter weather, I need to put thicker oil,’ or ‘Colder weather, I need to put thinner oil,’” Shelton said. “There are some manufacturers that will actually recommend a different viscosity or thickness of oil based on the time of the year that the vehicle is being operated at. But most manufacturers will stay with a single — typically like a multi-grade type — oil that they'll use year-round, and we're going to use the owner's manual as our guide for that.”

2. Embrace regular maintenance year-round.

Checking fluid levels is one part of a good preventive maintenance (PM) strategy, but there’s a lot more to consider when it comes to protecting your vehicles from the elements. Shelton’s biggest advice, though, is to make sure you’re taking care of it well before it becomes an issue.

“Remember that maintenance is a proactive action,” Shelton said. “It should not be reactive.”

As with fluid levels, you should always follow OEM recommendations in creating your PM schedule. While to some the recommendations may seem too frequent or the products too expensive, it’s important to remember that manufacturers make those guidelines for a reason.

“[The vehicle owner’s manual] should always be your guide,” he said. “You see a lot of advertisements, ‘Try this new fluid or try this new cleaner — you're going to get 10% increase fuel economy.’ With the money that OEMs put into research and engineering, do you not believe that if you could get 10% more fuel economy, that the manufacturer would be using that?”

Once you have your PM schedule in place, you’ll likely find that you save time and money by avoiding weather-related incidents that could have seriously impacted your HVAC fleet otherwise.

“Spend the money upfront because in the long run, it's going to pay for itself,” Shelton said.

3. Partner with a third-party maintenance provider that can be available when you need them.

Being able to find the right auto shop to partner with is the linchpin in your fleet maintenance approach, especially when extreme weather is a factor. You’ll want to look for a provider that’s available around the clock so you can reduce vehicle downtime and lessen impact on your technicians’ schedules.

“A lot of your service providers will require appointments,” Shelton said. “A lot of times, you can't schedule when that serpentine belt is going to break or when a tire blows out. So, you need to have a place that is willing to allow you to just show up at their doorstep and say, ‘Hey, uh, we need to replace the serpentine belt today,’ and they'll take care of you then.”

You’ll also want to be sure that your maintenance provider can be easily accessible in terms of distance, especially if you service a larger region in multiple counties. Providers that have multiple locations also often have the ability to store your vehicle information in a way that makes it available to every shop, so you can easily access vehicle history at any location you go to.

“Jiffy Lube, for example,” Shelton said. “When you pull in and you give them your VIN, they know who you are. They know all the maintenance that has been done not only at that facility, but at any Jiffy Lube in the system.”

4. Know your areas of service and their individual weather quirks.

Every region of the U.S. has its own unique climate and weather patterns, and knowing exactly what you’re up against can help you tailor your PM schedules so that you’re addressing the issues most likely to affect your vehicles, down to the smallest details

“Here in Traverse City [Michigan], we use sand on the road, but downstate, they use salt,” he said. “So, when you have the salt mixed with the water on the road, it sprays up on your windshield. It actually will coat your windshield. It'll make your window opaque. You can't see through it. So, you end up using a lot of washer solvent, like I've gone through a gallon of washer solvent in a day.”

Compare those road conditions with a place a little more southward, like Alabama or Georgia, where drivers are more likely to experience hotter, humid conditions that can cause engines to overheat faster than they might in Michigan during the same time of year.

5. Prepare emergency supplies in the cabin.

When something happens to a fleet vehicle that’s out on the road, chances are your technicians may end up stranded for a bit while they wait for the weather to pass or a tow truck to come and get them. Recent news has highlighted stories of people who have ended up stranded for hours and even days in inclement weather, so making sure each vehicle has adequate emergency supplies can be a huge lifesaver.

You’ll want to cover the obvious emergency tools, like jumper cables or spare tires, but also consider things that will benefit technicians driving the vehicles as well.

“One thing a lot of people don't think about is a cell phone battery pack,” Shelton said. “And when your battery gets low, most people think, ‘Oh, I just plug it into my car and it will be charged.’ Well, what if the reason you're on the side of the road is because the battery went dead? Now your phone went dead.”

Shelton recommends having vehicle specific tools, like ice scrapers, sand for traction, extra fluids, and basic tools, as well as items for health and comfort, like blankets, food and water, and even extra medications that the driver might need to see them through any potential roadside incidents.