Do cars use more fuel in winter?
Do cars use more fuel in winter?
How Winter Weather Affects Fuel Economy
Posted by PS Energy Group on Nov 29, 2016 10:00:00 AM
If it seems that your fleet requires refueling more frequently as the mercury slides lower, it’s not your imagination. Colder temperatures and winter driving conditions can mean, among other things, increased idle time, lower tire pressure and heavier rolling resistance, all of which can have a significant impact on fuel economy, no matter how responsible your drivers are or how carefully your vehicles are maintained.
But, fear not; Old Man Winter does not have to get the best of you and wreak havoc on your fuel budget. Taking the bite out of the winter fuel blues by gaining more control is as simple as knowing why winter weather conditions increase fuel consumption and knowing what steps you can take to “slow the flow.”
So, let’s take a closer look.
Generally, 75-85 degrees (F) is the ideal outside air temperature for optimal MPG. Once the temperature goes below 68 degrees, mileage starts to decrease rapidly, with the biggest MPG drops occurring under 45 degrees—as much as 20-28% from the summer months.
- Aerodynamic Resistance is Greater in Winter
The aerodynamic drag of a vehicle is proportional to air density. Cold winter air is denser than warm and humid summer air and, thereby, increases wind resistance, which, in turn, increases fuel consumption by approximately 1.3%. Additionally, wind speed is higher in winter, which increases total aerodynamic drag and, subsequently, lowers fuel economy.
According to the U.S. Environmental Protection Agency (EPA), poor road conditions can increase fuel consumption anywhere from 7-35%. Slush, snow, ice, sand, gravel and salt all contribute to asphalt deterioration, meaning vehicles have to work harder to overcome the increased rolling resistance and push through road covering. Working harder means more fuel burned, as does wheel slippage, which is caused by roads covered in snow and/or ice.
- Winter Gas Has Lower Energy Density
The volatility of gas, which determines how fuel is evaporated, is adjusted for the time of year. Winter-blend fuel has a higher RVP—Reid Vapor Pressure—because the fuel must be able to evaporate at low temperatures for the engine to work properly. According to the EPA, winter-blend fuel contains 1.7% less energy than summer-blend fuel, so gas mileage is lower. However, winter-blend fuel contains more butane, which makes it less expensive than summer-blend. Diesel is similarly affected.
- Higher Loads on the Electrical System
Colder temperatures mean an increase in the use of electrical accessories, including lights, defrosters, heater blower motors and windshield washer pumps to clean off road spray and remove ice from windshields. Since these are all powered by the electrical system, which gets its power from the engine, the more you use them, the more the engine works and the more fuel you burn.
An engine takes longer to warm up in colder temperatures and reach its most fuel-efficient temperature. This affects fuel economy the most on shorter routes more so than on longer ones, as vehicles on shorter routes are being operated at a less-than-optimal temperature and, consequently, are not burning fuel as efficiently.
As temperatures drop, tire pressure drops. For every 10-degree (F) change in air temperature, tire pressure decreases on an average of one to two psi—with a drop of one psi reducing fuel economy by 0.4%.
Getting better fuel economy in the winter months does not require drastic changes. Simple actions can make a big difference. Take a look at these recommendations from the EPA on how to improve mileage in cold weather and be sure to share them with your drivers. Improving fuel economy in winter is all about driving smarter—not harder.
- Park vehicles whenever possible in a garage or covered space to increase the initial temperature of the engine.
- Combine trips/routes to reduce the amount of time vehicles are operating with a cold engine.
- Keep idling at a minimum. Warm vehicles up for about 30 seconds and proceed gently rather than putting the pedal to the metal.
- Check tire pressure regularly and have a tire gauge in the vehicle at all times.
- Use seat warmers, window defrosters, interior lights and heater blowers only when absolutely necessary.
- Remove accessories that increase wind resistance and are not necessary for the job at hand—for example, roof racks.
To get more information about preparing your fleet for the cold (and for just about anything else), download our checklist, Preparing Your Fleet for Disaster .
E10 fuel and cold weather are ‘dropping fuel efficiency’ at dramatic levels
Drivers across the UK are having to fill their tanks more often due to a combination of low temperatures and the new E10 fuel. Despite E10 being introduced as an environmentally-friendly measure, some car owners are seeing marked reductions in how far they can travel on a tank, meaning more trips to the forecourt.
Cars that run on conventional petrol see their fuel economy drop by some 15 percent when outside temperatures drop in the winter, according to the US Dept of Energy.
For shorter trips of under five miles, that can be as much as 24 percent.
In hybrid vehicles the effect is even more pronounced with a drop in miles per gallon (MPG) of up to 34 percent.
And due to the reported reductions on mileage seen by motorists filling up with E10, that’s leading to an even bigger drop, hitting drivers in their wallets.
Drivers queue up at a forecourt during the crisis in October 2021 (Image: PA)
Motorists in the UK have been shocked at how E10 is impacting on their vehicles, with some telling of a reduction in how far they can travel of up to 20 percent per tank.
The replacement for E5 was brought in by the Government in September as a greener option due to it burning less fossil fuels.
But that benefit could be wiped out with drivers filling up more than ever.
And the winter months are proving to be a double-edged sword for car owners.
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Cars are much less fuel efficient in cold temperatures due to a number of factors.
Engines and gearboxes produce more friction because of cold oil and fluids, meaning they work harder.
It also takes longer for a car to reach its most fuel-efficient temperature, which is why short trips are especially thirsty.
Tyre pressures reduce in the cold, increasing rolling resistance, and cold air is denser, producing more aerodynamic drag.
A man fills up with petrol in the UK — users of E10 are seeing much reduced fuel efficiency (Image: PA)
Express.co.uk has previously reported on how E10 is potentially more likely to freeze than conventional fuels in the winter.
Dr Dan Clarke, Global Head of Science and Technology at SulNOx Group Plc said: “The main problem is that the additional bio-ethanol content in E10 prefers to mix with water as opposed to petrol.
«Where there is sufficient of both, it leaves the petrol and combines with the water to form a separate layer at the bottom of the fuel tank.
«The fuel line then draws from this watery alcohol mixture which is pumped directly into the engine.
“Equally, while petrol or diesel are very unlikely to freeze in the temperatures we typically experience in the UK, water condensation left in the empty fuel lines can easily freeze and prevent fuel from reaching your engine.»
The most common cars not compatible with E10 fuel (Image: Express)
Drivers can take some action to mitigate a winter reduction in MPG by following some simple steps.
They include using engine oil made for colder temperatures, parking in warmer spots to increase the initial temperature of the engine and not using defrosters more than necessary.
And running the engine while idling could actually be less effective — it’s better to drive off after 30 seconds because an engine will warm up faster being driven, and be more fuel efficient.
Owners of plug in hybrids or electric vehicles can increase their range by using the seat warmers rather than the main cabin heaters.
- Drivers could face £5,000 fines for headlight issues this winter
- Driver given £70 for parking at ASDA for just 13 minutes
- Green POLL: Should private car ownership be banned in UK cities?
How to maximize your car’s fuel economy to improve gas mileage and save money
Gas prices are nearly $1 higher than they were this time last year
By Steven Yablonski Source FOX Weather
Preparing your car for winter weather is a must
Here’s what you need to know in order to prepare your vehicle for whatever winter has in store.
Cold temperatures and winter weather significantly affect your vehicle’s fuel economy, but there are some things you can do to improve gas mileage that will save you some money.
According to the U.S. Department of Energy, a conventional gas-powered car’s gas mileage is about 15% lower when it’s 20 degrees than it would when it’s in the mid-70s and can drop to as much as 24% for shorter trips on the road.
And for hybrids and electric vehicles, the effect is even more significant.
There’s a variety of reasons why this happens.
Fluids in your engine move slower when it’s cold outside, thus lowering your vehicle’s fuel economy. It also takes longer for your engine to reach its optimal fuel-efficient temperature, which affects your vehicle more if you’re taking a shorter trip.
Warming up your vehicle before driving wastes gas, too. If you’re idling, your car is getting 0 miles to the gallon.
Using heated seats and window defrosters also uses more power, thus causing you to put more gas in your vehicle sooner.
Here’s how to improve the fuel economy of your car during the winter
7 things you need to know about winter driving
Winter driving season is here and knowing the science may keep you safer on the snow and ice.
Many people living in colder climates may not be able to completely mitigate the effect cold weather has on a vehicle’s fuel economy, but there are some things you can do to improve the gas mileage.
If you can, try to park your car in a warmer spot, like a garage. According to the DOE, that can help increase the internal temperature of your vehicle.
Since shorter trips can end up costing you more at the pump, in the long run, try and combine as many trips as possible so that you’re not making too many drives with a cold engine.
Also, don’t let your car sit and warm up for too long. According to the DOE, most car manufacturers recommend starting to drive after about 30 seconds. At that point, your engine will begin to warm up faster. That will also help the interior heat up quicker.
Try not to use seat warmers and window defrosters more than you need to, and remove anything that will increase resistance, like a roof rack.
And since tire pressure decreases in the winter, make sure they’re properly inflated. Underinflated tires won’t allow for proper traction, which can lead to your vehicle needing to use more energy.
Extra tips for plug-in hybrid and electric vehicles
Do you have a hybrid or electric car? There are some other ways you can save on gas mileage, too.
If you’re driving a plug-in hybrid or electric car, preheat your vehicle’s interior while it’s charging because the DOE said that can increase the range of your vehicle.
Also, while the vehicle is plugged in, use the seat warmers instead of the heater because that can save you energy and extend the range of your car.