Hybrids Not Living Up To Gas Mileage Claims
Driver’s of hybrid vehicles are often disappointed to find that the gas savings they’re getting is significantly lower than what was promised by the showroom MPG sticker on the window when they purchased the car.
An article in Automotive News investigates the reason for the mileage discrepancy, which has led to lawsuits by owners against companies like Honda, Ford and Toyota who make the hybrid vehicles.
Consumer Reports tested hybrids for gas mileage discrepancies and found that the biggest gap between automakers claims and actual mileage occurred in the Ford C-Max Hybrid and the Ford Fusion Hybrid. Their test on the Fusion resulted in 39 mpg overall, 35 for city driving and 41 on the highway, as opposed to Ford’s claim of 47 mpg overall. The C-Max got 37 mpg on average, with 35 and 38 respectively for city and highway driving, as opposed to Ford’s claim of 47 overall. Bear in mind that the manufacturers post these mpg ratings as estimates that depend on a variety of factors and that Consumer Reports says that the vehicles still get excellent mileage, despite the discrepancy.
Why do hybrids fail to measure up to promised fuel consumption claims? Cold weather driving is one of the main culprits when it comes to decreasing the number of miles they manage to squeeze out of each tank of gas. One reason for this phenomenon is the fact that gasoline sold in cold winter climates is mixed with additives that keep it from freezing. That means there’s less energy in the fuel. Another reason is that it takes more energy to power a vehicle in cold weather because the lubricants are thickened by the low temps. The use of heaters, window defrosters and heated exterior mirrors also gobbles additional fuel.
Another robber of fuel economy is driving style. Hybrids gain better mileage when they’re driven at speeds less than most highway limits. Driving with constant braking and acceleration variations is also a stealer of gas mileage in hybrids, as well as in conventional gas vehicles. Using air conditioners, heaters and other energy robbers also drives up the amount of fuel used by the vehicles.
Speed is another factor in determining gas mileage, because the amount of fuel used increases dramatically at speeds over 55 miles per hour. Driving a vehicle at a speed of 70 miles per hour uses 25% more fuel than driving at 55. Hybrids tend to get the best fuel savings in city stop and go traffic, because they operate mostly on battery power during this type of driving. On the highway, the additional power required to move the weightier battery also uses more fuel.
To address the issue of the mileage discrepancy, Ford has just lowered the fuel mileage estimate on the C-Max Hybrid. The window sticker now gives it a fuel rating of 43 mpg overall, 45 mpg city, and 40 mpg highway.