Hybrid Vehicle Fuel Economy Issues

The question of claimed fuel economy versus actual fuel economy is a volatile one when it comes to hybrid vehicles.  Recently, a San Diego women sued Honda in small claims court and won a judgement against Honda, presumably because her Honda Civic hybrid did not get as good of gas mileage as she expected and/or as Honda claimed it would.

Here are my personal experiences, drawn from driving thousands of mile under varying conditions in a wide range of hybrid vehicles.  Hopefully they will serve to help your expectations regarding your own hybrid vehicle.

Fuel Economy in town versus highway:

Despite EPA ratings, only one hybrid vehicle I know of actually has similar or slightly better fuel economy in town versus highway driving; that vehicle is the Ford Escape hybrid.  EVERY OTHER hybrid vehicle I have driven gets worse gas mileage around town as compared to on the highway.  My 2004 Prius, at 65 mph average highway speeds will do 47 mpg.  Around town, that number drops to 40 mpg and I am a conservative driver.  Our 2002 Toyota Prius shuttle car averages 37 mpg, 100% in-town driving.

Wind:

A strong side or headwind is the worse indicator for fuel economy.  Even the aerodynamic design of the hybrid is no match for a strong headwind.  Expect as much as a 10 mpg drop in mileage as the result of a stiff headwind.

Tires, low rolling resistance versus standard:

Standard tires cost an average of 2-4 mpg in fuel economy, when compared to low-rolling resistance tires.

Speeding:

If you plan to drive 75-80 mph in your hybrid, expect a drop of 3-5 to mpg over your typical 65 mph mileage.

Mountainous or hilly country:

Cities like San Francisco or San Diego have lots of hills.  In spite of hybrid advantages using regenerative braking that conserves some fuel, expect lower numbers under those conditions.  Bear in mind that the hybrid vehicle cannot change the laws of physics.  It takes more power and therefore more fuel to push a vehicle faster or up a hill or against the wind.  No change in technology is going to modify that absolute condition.

Average fuel economies by vehicle, per my experience, in typical in-town (Hemet) driving and 65 mph highway driving, no wind:

2001-2003 Prius: 37 mpg in town, 43 mpg on highway

2004-2009 Prius: 40 mpg in town, 47 mpg on highway

2010-2012 Prius: 42 mpg in town, 47 mpg on highway

2000-2007 Insight: 50 mpg in town, 60 mpg on highway

2003-2005 Civic: 35 mpg in town, 41 mpg on highway

2006-2012 Civic: No personal experience to go by.  Technology would indicate a slight improvement over earlier Civic.  Please e-mail me if you have first-hand experience so I can add the numbers here.

2005-2007 Accord: 26 mpg in town, 37 mpg on highway (note: highway mileage at speeds about 70 mph drops off rapidly)

2010-2012 Insight: No personal experience to go by.  During our hybrid rally, the one Insight got an impressive 66 mpg, but that sort of driving is not practical for regular driving.

2004-2012 Escape: 31 mpg in town, 32 on mpg highway.  Drafting behind a large truck, I was able to improve the highway mileage to 38 mpg.  This is not considered a safe practice and is not recommended, but it is highly effective at reducing wind resistance and thus improving mileage.

If you have time and don’t need to get somewhere in a hurry, drop your speed to 55 mph and watch your fuel economy improve to the maximum best.