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Solving the fuel economy riddle

"As the price of regular gasoline nudges $1.30 per litre in our area, my thoughts turn to saving fuel."

As the price of regular gasoline nudges $1.30 per litre in our area, my thoughts turn to saving fuel.  In particular it is about time I started driving a fuel efficient vehicle again.  It has been a while.  Kids, bikes, and a boat make travel in a small fuel efficient vehicle not practical.  How many different vehicles does a person need?

You are not going to save much money buying an extra fuel efficient car if you still need the inefficient ones for hauling people and stuff.  An extra vehicle has a lot of extra expenses and fuel is only one of them.

Bragging rights for the highest fuel efficiency for various vehicle types is bantered about a lot in new vehicle marketing these days.  The numbers you are starting to hear seem pretty amazing.  Canadian numbers are the most exciting to me especially when delivered in the miles per gallon format

A full size pickup truck that gets 36 miles per gallon.  Hybrid full size pickups that get 28 miles per gallon in city driving.  61 miles per gallon diesel cars.  81 miles per gallon hybrids.  These are some big numbers.

Does anyone ever achieve these numbers?  Once in awhile maybe?  (Sure, we all know those people that even report exceeding those numbers significantly but do we believe them?  Not likely.) Not regularly.  There are even some lawsuits on going because consumers are not getting these advertised numbers, no matter how hard they try.

In Canada your new car has an Energuide sticker on it.  The test procedure that produces those numbers is a very controlled test that simulates both city and highway driving.  The key word is simulates.  It is called the Federal Test Procedure or FTP.

There is a standard in the US and a similar one in Canada that makes manufacturers achieve fleet fuel economy averages. In a nutshell the average fuel economy of the sold vehicles for the given model year must be above a predetermined number. Bigger vehicles are allowed a lower average.  The U.S. numbers are currently about 37 U.S. miles per gallon for small cars and 28 U.S. miles per gallon for large cars.  In the U.S. it is called CAFE (Corporate Average Fuel Economy) and in Canada we have the similar CAFC (Company Average Fuel Consumption).

So the manufacturers need to meet or exceed these averages.  Therefore, they must produce and sell some vehicles with exceptional fuel economy numbers. They definitely build vehicles that produce great numbers in the FTP (Federal Test Procedure).  They actually perform and report the results themselves.  Ultimately they set up the vehicles to produce big numbers in these tests.

Then we have the real world.  Read the small print on a new vehicle’s Energuide sticker and you will see the disclaimer.  “Your mileage will differ”.  How you configure your vehicle and drive your vehicle will affect your mileage.  Choosing a trailer towing package on your truck will likely decrease your fuel mileage.  Choosing those bigger tires and wheels will not improve your mileage.  Canada’s cold climate will reduce your ultimate fuel mileage number.  The list goes on.

If you use the Energuide sticker fuel efficiency rating to choose your next vehicle I would not put much value to small differences in fuel efficiency ratings.  Try to seek out some real world numbers if fuel efficiency is a big concern for you.  Let google be your friend.

Trail’s Ron Nutini is a licensed automotive technician and graduate of mechanical engineering from UBC. E-mail: nutechauto@telus.net