Test your miles-per-gallon knowledge

During the past 20 or 30 years, with gasoline readily available and cheap — at least by today’s standards — many drivers took the hard-earned lessons of the 1970s fuel crisis and filed them away under “Old News.” Nowadays, however, they’re taking a second look at what we learned back in the days of the Arab oil embargo.

In today’s world of financial, environmental and sociopolitical worries, conservation should be a matter of habit for any driver, practiced daily because it benefits your car, your pocketbook, your environment and — as I’ve been preaching in “American Drivers Fight Back” — your country.

Here is a 10-question quiz to help you see how much you’ve remembered, how much you’ve forgotten and how much you never knew.

Driving Questions

1. Americans do most of their driving on trips of: a) 100 miles or more. b) 50-100 miles. c) 15-50 miles. d) 15 miles or less.

2. True or false: At speeds of 45 mph or more, open windows help increase gas mileage by allowing the onrushing air to flow smoothly through the car, reducing wind resistance.

3. Mileage-marathon drivers, who compete to drive long distances while achieving the best possible gas mileage, pay close attention to: a) minimizing rolling resistance. b) increasing engine efficiency. c) improving driving techniques. d) none of these. e) all of these.

4. True or false: In general, the narrower a tire’s tread, the better mileage it will provide.

5. One of the least costly, easiest and most effective ways to improve your gas mileage is to: a) get an engine overhaul. b) have your engine tuned. c) keep your tires at the recommended air pressure. d) borrow your neighbor’s car.

6. One of the best gas-saving techniques when driving in the city is to: a) try to be first at the next stoplight. b) start very slowly from all traffic lights and stop signs. c) decelerate when approaching all stops and slowdowns. d) all of the above.

7. It is best to turn off your engine and then restart it, rather than letting it idle for the duration, if the period of anticipated idling is more than: a) a few seconds. b) 30 seconds. c) one minute. d) 10 minutes. e) 30 minutes.

8. True or false: The time of most pronounced engine wear and maximal gasoline consumption is the period immediately after you start your vehicle’s cold engine.

9. True or false: Moderate acceleration to your desired speed is one key to achieving good gas mileage from your vehicle.

10. Once past 45 mph, for every 5-mph increase in speed the average car pays a mileage penalty of how many miles per gallon? a) .5 mpg. b) 1 mpg. c) 1.5 mpg. d) 3 mpg. e) 5 mpg.

Driven Answers

1. d). And it’s those trips of five miles or less — the quick spin to pick up a newspaper or visit a nearby friend — that really eat the gas, because your car never has time to fully warm up. Whenever you can, combine errands to make three five-mile trips into one 15-mile trip, or simply walk or bicycle more often!

2. False. Because they increase wind resistance, as anyone who’s been buffeted while riding in an open-windowed car at high speeds can testify, open windows significantly reduce your gas mileage. At 55 mph, for example, the loss can amount to a hefty 10 percent.

3. e) All of these. These three elements are the prime focus of mileage-marathon drivers, and should also be the main targets of anyone concerned with fuel efficiency for any reason.

4. True. High-mileage experimental cars all have tires the width of bicycle tires.

5. c) Air is free, so use it. d) is a close second, though!

6. c) The deceleration mode, when the car is coasting to a stop or a slowdown, is a particularly efficient engine mode. The more you can use it — especially as opposed to accelerating and burning extra gas to get to an inevitable stopping point a moment sooner — the better for your fuel efficiency.

7. c) Recent research suggests that it’s actually more fuel-efficient to turn off the engine immediately even if you’re only going to be waiting for a few seconds, since idling is the least efficient form of engine operation, getting you 0 miles per hour. But, since we can’t have everyone turning off their engines at every stoplight, shutting off the engine for any wait longer than a minute is a reasonable compromise.

8. True — as everyone who reads this column, even occasionally, must know. Hence, the sooner you can move from idling into motion, gradually accelerating to full speed, the better your fuel efficiency.

9. True. Jackrabbit starts waste fuel, but so do mud-turtle starts. Begin to accelerate as soon as possible, but don’t be in any hurry to reach your desired speed.

10. c) Every 5 mph past 45 mph loses you 1.5 mpg in fuel efficiency. An engine that gets 20 mpg at 45 mph, for example, will get only 17 at 55 mph. Speed doesn’t pay, in short — it costs.