Does Cold Weather Affect Diesel Mpg?

It has felt like winter in Meridian, Idaho for a few weeks, but as of December 21st, it is officially winter.

Cooler temperatures and winter conditions can reduce your diesel pickup’s gas mileage and reduce the energy level of the gasoline. This occurs as a result of manufacturers altering the diesel fuel blend in order to prevent it from getting thick and gel-like. In the winter, the fuel is thinner and has less energy as a byproduct of the mixture.

Fortunately, there are several things you can do to reduce the impact of winter on your diesel fuel consumption. It is crucial to note, however, that while you can stretch the fuel a little longer, it will still not last as long as it does during the summer months.

Do diesel cars use more fuel in cold weather?

Fuel efficiency is roughly 10% worse at -5°C than it is at 20°C, according to official fuel testing. Furthermore, when temperatures drop below 0°C, fuel economy can drop by as much as 20% for vehicles travelling less than 4 miles – so what’s going on?

Given that petrol’s freezing point is a cold -60°C, a petrol tank will almost certainly not freeze during even the harshest British winter. Diesel, on the other hand, has a much lower freezing point and is more likely to gel in cold temperatures. To tackle this, fuel firms have developed a summer and winter diesel blend that can withstand temperatures as low as -5°C and as high as -15°C.

Given that neither fuel is significantly affected by cold weather, it’s evident that the problem isn’t with the liquid itself, but rather with the effect of the cold on the car’s mechanics.

Cold weather can impact a variety of components in your car, resulting in a significant reduction in fuel efficiency. We’ve compiled a summary of some of the negative affects that cold weather can have on your car’s fuel economy.

  • It takes much longer for your engine to achieve its ideal operating temperature on a cold day. This is especially problematic for short excursions, as the automobile will spend the majority of its time operating at a lower-than-optimal temperature, resulting in poor fuel economy.
  • In cold weather, engine oil thickens. This can cause friction between moving parts in the engine and transmission system, resulting in unnecessary fuel use.
  • Fans, defrosters, wipers, and heated seats are all electrical components that place additional demand on the battery. As a result, the alternator has a harder time keeping the battery charged, resulting in a decrease in fuel economy.
  • It’s common to have to warm up your automobile to defrost and demist the windscreen on bitterly cold mornings. This type of idling has a significant impact on fuel efficiency, with your automobile obtaining zero MPG for the duration.
  • Cold air is thicker and denser than warm air, which increases your car’s aerodynamic drag. This requires the engine to work harder, especially at highway speeds.
  • In extremely low temperatures, tyre pressures drop somewhat, increasing the vehicle’s rolling resistance.

Why is my diesel getting bad gas mileage?

Your fuel economy will undoubtedly be impacted if they are misfiring or not functioning properly. The flow of fuel into the engine might be severely hampered by a faulty fuel injector or a dirty/old fuel filter. One of the most prevalent causes of poor gas mileage is an issue with the fuel system.

Does cold weather affect diesel engines?

In cold weather, diesel engines are more difficult to start because they rely on high temperatures caused by compression to ignite the injected fuel. In fact, starting a diesel engine at 0°F (-17°C) is five times more difficult than starting one at 80°F (26°C).

Does cold weather affect fuel mileage?

MEMPHIS, TENNESSEE (WMC) – You may notice that your gas gauge goes down faster in the winter than it does in the summer when driving your car. Did you realize that the cold weather has an impact on your car’s fuel economy?

In this episode of The Breakdown, we explain why cars get fewer miles per gallon throughout the winter than they do in the spring and summer.

Fuel economy tests conducted by the US Department of Energy demonstrate that a typical gasoline car’s gas mileage is around 12% worse at 20 degrees Fahrenheit than at 77 degrees Fahrenheit in short-trip city driving. For very short excursions of 3 to 4 miles, it can decline by as much as 22%.

Why do diesels get worse mpg in winter?

Wind, snow, rain, and temperature are some of the most influential factors throughout the winter months. Crosswinds and headwinds dramatically increase aerodynamic drag, reducing fuel economy. Fuel efficiency drops by as much as 13% for every 10 mph of headwind or crosswind.

As the temperature of the ambient air drops, the air becomes denser, increasing aerodynamic drag. Aerodynamic drag increases by 2% for every 10 degrees Fahrenheit reduction in temperature. Every 2% increase in aerodynamic drag results in a 1% reduction in fuel economy.

Fueling stations will convert to winter mix fuels throughout the cold winter months. Winter blend fuels contain additives that prevent diesel fuel from gelling at high temperatures. These additives lower the cetane level of the fuel, resulting in a loss of one-half to three-quarters of a mile per gallon in fuel economy.

We find a considerable increase in the amount of time the engine cooling fan is operating during those extremely hot summer days. To run, a typical diesel engine needs between 15 and 30 horsepower. When the cooling fan is turned on when the engine is operating at 1450 rpm, the fuel efficiency drops by 8% to 12%. The primary function of the engine cooling fan is to keep the engine from overheating, but it also serves as part of the cab’s air conditioning system. When the A/C Freon compressor is turned on, a signal is sent to the engine cooling fan to turn on as well. The operation of the A/C Freon compressor accounts for approximately half of the overall fan run duration. Excessive engine cooling fan run duration might be caused by a malfunctioning A/C system.

We find an increase in engine idle time in extremely hot or cold weather to keep the cab and sleeper comfortable or cool. Idle time can have a big impact on your fuel economy. One gallon of fuel can be consumed every hour by a diesel engine running at 1000 rpm. Idling an engine for 8 hours at today’s gasoline costs may cost you $30.00. In a long-haul operation, every hour of idle time reduces fuel efficiency by 1%.

Because the tires must push their way through the precipitation on the road in addition to propelling the car, rain, snow, or slush on the road increases the vehicle’s rolling resistance. The tires, transmission oil, and axle oils are all cooled by the rain. At lower temperatures, these components perform less efficiently. In just a moderate rain, the additional rolling resistance and drive-train friction can increase fuel consumption by 0.2 to 0.3 mpg.

There are numerous factors that have a negative impact on fuel economy that are beyond our control. As a result, it’s critical that we maximize the efficiency of everything under our control in order to achieve the best possible fuel economy.

How can I get better gas mileage in my diesel?

  • Turn off the engine. Excessive warm-up times can deplete diesel fuel consumption, therefore avoid idling to save money.
  • When possible, use shore power. This is also known as truckstop electrification, because it allows drivers to plug in instead of idling, which helps to keep the vehicle cool while parked. Shower power is projected to save as much as $3,240 per year!
  • The engine should not be revved. Slowly transition to your next gear rather than as quickly as feasible. It’s a little less enjoyable, but it’s also a lot less expensive.
  • Find the sweet spot of your engine and ride it. Operating at the peak torque zone once you’ve reached your cruising speed provides you the most horsepower and diesel fuel mileage.
  • Make the most of your air conditioner by using it as little as possible. Running the air uses fuel, so if you can prevent it to save money, do so.
  • Be aware of approaching traffic signals. It is possible to save fuel by avoiding a complete halt. You’ll use less fuel if you can see the light is going to turn green and you can safely slow down without stopping.
  • Maintain a safe gap between you and the vehicle in front of you. The further you are from the vehicle in front of you, the less likely you are to have to stop. Stopping less also means avoiding excessive acceleration caused by braking.
  • Reduce your highway speed on a regular basis. While it may seem counterintuitive to get there faster, every mile per hour beyond 55 reduces your fuel economy by 0.1 miles per gallon.
  • Don’t slam on the brakes. To avoid fuel burn spikes, use smooth, constant gasoline acceleration.
  • Make use of your cruise control. You can avoid using the throttle to climb hills by utilizing cruise control to maintain a constant pace.
  • Use truckstops at the top of slopes if at all possible. Stopping at the top of a hill allows you to gradually return to the highway downhill, using less fuel. Alternatives can be found using the Multi Service Fuel Card truckstop locator.
  • When not utilizing cruise control, avoid accelerating excessively. Allow the truck’s momentum to carry it over the top of a hill to avoid slamming on the gas pedal too hard.

The Multi Service Fuel Card is responsible for the content on this page. Simply put, it’s the finest overall fuel card value on the market right now. We provide substantial credit lines, access to our Zero Fee and Rebate networks, industry-leading customer service, and more.

Excessive Short Trips

After your engine has warmed up, it is at its most efficient. When you only take short trips, your automobile does not have enough time to warm up completely, resulting in a higher overall fuel consumption.

Frequent Cold Weather Travel

Your car engine takes longer to warm up in cold weather, so it spends less time at the optimal temperature for fuel economy. Follow the suggestions in our blog “Way to Winterize: 8 Steps to Prepare Your Car for Cold Weather” to reduce the impact of cold weather on your MPG.

It’s important to remember that letting your automobile idle to warm up consumes gasoline rather than improving it.

Heavy Braking or Acceleration

Aggressive driving causes your automobile to shift gears faster than it should for maximum fuel economy. According to EPA tests, frequent, forceful braking and rapid acceleration can impair your fuel economy by up to 33% while driving on the interstate.

High Vehicle Weight or Towing Weight

Your engine has to work harder when your car is loaded down. A baggage or bike rack, a hefty internal load, or a trailer could all contribute to the added weight.


It’s no secret that a speeding ticket may be expensive, but speeding also consumes petrol more quickly. When you travel at speeds of 80 mph or above, you create more air resistance, which reduces your fuel economy.

Why is my mpg decreasing?

Bad gas mileage can be caused by a variety of factors, but the basis of the problem is that your car is not functioning properly. At the very least, this inefficiency is causing your wallet some grief at the pump, as you’ll have to fill up more frequently, but it could also be a hint of a larger problem on the horizon.

Here are some the main causes for a sudden drop in gas mileage:

  • The fuel mixture and your fuel efficiency will be affected by a bad oxygen sensor or air filter in any form.
  • Spark plugs that are bad or misfiring may cause poor performance and, as a result, a loss of power, which will cost you fuel efficiency.
  • Fuel injectors or fuel pumps that are dirty, bad, or leaking will impact the fuel mixture, resulting in poor acceleration, power loss, and fuel inefficiency.
  • Use synthetic oil that will reduce friction if the oil quality is not up to or beyond your vehicle’s recommended level.
  • Tire pressure and/or alignment issues-tires with low pressure or that are out of alignment can reduce fuel economy.
  • While you’re not using the air conditioner, remember to switch it off or defrost it when you’re not using it.
  • If your vehicle is dragging to one side, this could be a symptom of a blocked brake caliper, which feels like tugging on your own cape.
  • Check out your personal driving tendencies. Have you turned into a revving machine, a more aggressive driver, or are you warming up your car more than usual because of the chilly weather? All of these habits can help you save money on gas.

Each visit and/or oil change at Fifth Gear Automotive in Lewisville, TX includes a complete evaluation of your vehicle’s systems to ensure it is running at its best. Call Fifth Gear Automotive for a full check by one of our ASE certified experts if you are experiencing any of these symptoms.

Fifth Gear Automotive, a family-owned independent auto repair shop, has over 100 years of experience with all domestic and import makes and models, specializing in European auto repair, and has been serving Lewisville, Highland Village, Flower Mound, Lantana, Double Oak, and the surrounding communities for over 14 years. We have one aim in mind for all of your auto repairs: complete customer satisfaction.

Are diesel cars less efficient in cold weather?

Yes, diesel is more cost-effective in hot weather than in cold or cooler weather because there is less friction to overcome and so less fuel is required; additionally, the warmer fuel/air compressed mixture ignites more easily, requiring less fuel to compensate.

How cold is too cold for diesel?

When it comes to diesel trucks, how cold is too cold? At 15 degrees Fahrenheit (-9.5 degrees Celsius), the diesel fuel in your fuel tank will gel and you will have problems starting your engine. Your diesel vehicle will have troubles if the temperature drops below 15 degrees Fahrenheit / -9.5 degrees Celsius. The diesel won’t be frozen solid, but it won’t be liquid either. You must now rely on heating solutions such as block heaters and glow plugs, which are not available on all diesel engines.

There’s a lot of debate regarding what temperature is too cold for a diesel truck. On the internet, it is stated that the freezing point of diesel fuel is roughly -112 degrees Fahrenheit or -80 degrees Celsius. Now you believe you will never be in a region that gets that cold, so you should be fine. Wrong.

It is not necessary for the diesel in your fuel tank and fuel lines to be solidly frozen to cause you problems. When the temperature drops below 15 degrees Fahrenheit / – 9.5 degrees Celsius, the diesel fuel begins to change shape and becomes more like a gel. Consider a gel-like fuel that travels from the fuel tank to the engine. Traveling through the fuel lines would be difficult, and you would have difficulty starting your engine in the frigid winter.