What time of day is best for buying fuel or charging your EV?

If your business has (or operates) a fleet of commercial vehicles, optimizing fuel efficiency is one of the most important considerations for reducing your bottom line and ensuring smooth operations. Whether you operate a fleet of internal combustion engine (ICE) vehicles, electric vehicles (EVs), or a mixed fleet, a key factor to maximizing fuel efficiency is strategically planning fueling along routes. Data compiled by WEX shows that there are optimal times of day to purchase fuel along with best times to charge EVs. The following tips can help fleet managers reduce fuel costs and keep their company’s vehicles running efficiently.

Your fleet of commercial vehicles can save money on fuel

If your fleet is looking to increase fuel efficiency or simply save money, using a fleet card and telematics solution will have a positive impact on your bottom line. With the use of mobile apps and GPS fleet tracking, your drivers can find the most affordable fueling stations along their route. You can also take the savings one step further by planning out where a driver will need to refuel along the route in advance. Instead of the driver searching for the lowest prices while en route, fleet managers can plan the most affordable fueling location, as well as the best day of the week and time of the day to refuel. Prices at the pump change throughout the day and week.

As with refueling your ICE vehicle, there are optimal times to charge EVs. For mixed-energy fleets that operate electric or hybrid vehicles that need to be charged, management should create best practices for drivers to maximize battery efficiency. Implementing charging and refueling procedures can help your company save money on fuel and EV charging.

Best times to fuel your fleet of company vehicles

Whether your fleet of company vehicles drive hundreds of miles a day or stay local, you can still save money at the pump. You don’t need to have the most recent vehicle make or model to achieve better fuel efficiency either. The way your fleets are driven, and how they’re fueled and maintained, are a few of the most important variables to getting the most out of what you put in your tank.

Fuel in cooler weather

The best time to refuel your vehicle is when the weather is cool. Fuel expands and contracts when it’s hot versus cold, so the volume of fuel in your tank can vary depending on the time of day and the temperature. Another consideration of how temperature impacts fuel, is that all service stations store their fuel in underground tanks. When the temperature is cooler, fuel is denser and takes up less space. This means that when you fill up your tank during the early morning or late at night, you are getting more fuel for your money. On the other hand, when the temperature is warmer, fuel expands and takes up more space, which means that you may be getting slightly less fuel when you fill up during the hotter hours of the day going into summer. In the long run, fueling timing can have a $0.10 difference per gallon for your fleet, making a significant impact in fuel expenses over the course of a year.

This being said, the best time to buy fuel is:

• Fuel your fleet early in the morning
  • Data from the past four years shows fuel prices are traditionally lowest between 7am to 8am. Not only is this a peak commute hour, so more people are purchasing fuel, but the temperature is cooler in the morning. This is an optimal time to fuel your fleet because the prices are cheaper and the temperatures are typically cooler than they are in the middle of the day.
• Fuel your fleet late at night
  • Similar to the early morning, temperatures will be cooler in the evening. This time is also optimal for drivers and fleets looking to avoid wait times at the pump during peak business hours.

Best days of the week to fuel your fleet vehicles

Prices are not always consistent every day of the week. For instance, people tend to travel on the weekends, therefore more fuel is likely to be purchased during weekend days. Fueling stations will likely increase the price of fuel on Friday, Saturday, and Sunday to make a higher profit. Hence, it is not the most cost-effective time to purchase fuel for your fleet. Instead, try purchasing fuel earlier in the week when possible, like Monday, Tuesday, and Wednesday.

These tips can help your fleet save money at the pump

Don’t wait until you’re on empty to fuel your fleet of vehicles

When it comes to maximizing your fleet’s fuel efficiency, there are several strategies beyond timing your fueling just right. Another important, science-backed tip to note is to avoid waiting until your tank is empty before refueling. Fuel can evaporate when exposed to air, which is why the fuel storage tanks are designed with floating roofs to reduce contact with the atmosphere. This means that driving a vehicle with a nearly empty tank makes the remaining fuel evaporate more quickly. Filling your tank before it is empty ensures that you always have reserve fuel available and reduces the risk of running out, and the recommendation is to refill the tank once there is a quarter of a tank remaining.

Fill up your tank all the way and slowly when you fuel your fleet of vehicles

To further optimize fuel usage, it is crucial for drivers to fill their fuel tanks all the way up when they’re at the pump. This ensures that your fleet is maximizing range and minimizing the number of refueling stops. Additionally, remind your fleet drivers to fill their tanks up slowly when possible to reduce the amount of fuel vapor lost during the fueling process – every drop counts!

Stay at the speed limit to conserve fuel

Another effective way to save money at the pump is by maintaining a consistent pace and adhering to the speed limit. According to the US Department of Energy, each 5 MPH you drive over 50 is like paying 14 cents more per gallon of fuel. By avoiding unnecessary acceleration and quick decelerations, maintaining a steady speed can improve vehicle fuel efficiency as well. According to the US Department of Energy, obeying the speed limit, accelerating and braking gently and gradually, and reading the road ahead can improve the fuel economy of your vehicle by 15%–30% at highway speeds and 10%–40% in stop-and-go traffic.

Keep tires inflated on your fleet of vehicles

Lastly, it is important to remember the impact properly inflated tires can have on miles per gallon and overall fuel efficiency. Keeping your fleet’s tires inflated to the vehicle’s recommended pressure results in better fuel economy. According to the US Department of Energy, maintaining the appropriate tire pressure enhances fuel efficiency, with estimates that properly inflated tires may boost mileage by as much as 3.3%. Conversely, for each 1-psi drop in pressure, under-inflated tires can potentially reduce fuel mileage by 0.3%. This is a simple yet effective way to enhance fleet vehicle performance and ensure you’re achieving the maximum miles per gallon. This is another reminder on the importance of regular maintenance checks for fleet vehicles.

Best times to charge your fleet of EVs

EV fleet adoption has increased in the last nine months, and the refueling procedure is vastly different for an EV than it is for an ICE vehicle. With this shift toward more EVs on the road, fleets need to assess their fueling practices and implement strategic route planning to create charging efficiencies. One ideal opportunity to increase efficiencies for your EVs is crafting routes to include public charging stations. According to the US Department of Energy, public direct-current fast-charging (DCFC) stations are increasingly accessible along major transportation corridors, allowing EVs to extend their range and provide convenient charging options. Parking at these public charging stations while at work in the vicinity allows drivers to optimize fuel efficiency when the vehicle is idle during the day. By taking advantage of these opportunities during scheduled stops, your fleet can minimize charging time and ensure vehicles are sufficiently powered to complete their routes.

The optimal time to charge an EV is at night when the vehicle is idle. By charging vehicles overnight, you should be able to take advantage of off-peak electricity rates and ensure that they start each morning with a fully charged battery. This can be done at the driver’s home or in a charging facility. Depending on the range of your EVs and their daily mileage, a full charge in the morning may be sufficient to meet your fleet’s routes for the entire day, eliminating the need for further charging until the end of the day.

These tips can help your fleet save money when charging with electricity

When it comes to charging your electric fleet, there are several best practices that can help your business save money and maximize efficiency. A simple technique to implement with your drivers is regenerative braking. This is a feature not shared with ICE vehicles: recapturing energy while on the road.  Electric vehicles are equipped with regenerative braking systems that allow vehicles to recover and store energy generated during braking or deceleration. Research done by J.D. Power shows that by employing regenerative braking, the vehicle’s electric motor can decelerate the car while capturing and redirecting up to 70% of the energy that would typically dissipate, channeling it back into the battery for recharging purposes.

Another consideration for battery powered electric vehicles is the 80/20 rule, similar to smartphone battery charging best practices. Essentially, an EV’s battery will last longer if you prevent it from charging 100% or running the battery down to zero. Adhering to the 80/20 rule means not charging your EVs past 80% capacity and not letting your charge go below 20%. By maintaining this range of charging, the longevity and efficiency of your EV batteries is increased. Most EV have touch screens allowing your drivers to select the specific desired charge level when you’re plugging in overnight.

However, the 80/20 rule may not apply to every vehicle or situation. Some EVs may recommend charging the battery to 100% or drivers may need the full charge for more range during longer routes. This is entirely dependent on each fleet business, and the make-up of the fleet.

Lastly, when considering the charging infrastructure for your fleet, it’s crucial to assess the specific needs of your vehicles. Different types of EVs may require different charging options, such as Level 1 charging (using a standard household outlet), Level 2 charging (using dedicated charging stations), or even DC fast-charging for quick top-ups. By ensuring that the charging infrastructure matches the requirements of your fleet, you can streamline the charging process, minimize downtime, and optimize efficiency.

Increase fleet efficiency with a strategic fueling plan

For fleets with a mix of hybrid, ICE, and electric vehicles, a combination of the strategies we outline above can work to help you increase fuel efficiency and increase your bottom line. Your fleet can use the information we’ve provided for route planning, optimizing fuel expenses, and improving the efficiency of your fleet. By implementing these tips and techniques, you should be able to save money on fuel, extend the lifespan of your batteries, reduce charging times, and enhance the overall fuel efficiency of your fleet. Embrace these strategies and watch your fleet’s efficiency soar, leading to cost savings and greener, more sustainable operations.

To learn more about WEX, a dynamic and nimble global organization, please visit our About WEX page.

Apply for a fleet card today!

Sources:
US Department of Energy
J.D. Power
Fuel Economy
Ok Carz
Energy.gov

The data aggregation and analysis was provided by Christopher Castor, Growth Data Analyst for WEX. Christopher recognizes that this research and data is critical to helping fleets maximize their operations and reduce their bottom line.

Editorial note: This article was originally published on July 11, 2023, and has been updated for this publication.