Is a road trip part of your summer travel plans?  If so, you’re probably looking for ways to save money at the gas pump.  While the best way to burn less fuel is to buy a car more fuel-efficient car, tests done by Consumer Reports show there are ways to improve the mpg you get with your current car.

1. Drive at a moderate speed

Speed is the biggest factor affecting mpg. Driving at 55 mph instead of 65 or 75 will save you money. For example, when Consumer Reports increased a Toyota Camry's highway cruising speed from 55 mph to 65, the car's fuel economy dropped from 40 mpg to 35. Speeding up to 75 mph cost the car another 5 mpg. One reason is aerodynamic drag increases exponentially at higher speeds; it takes more fuel to power a car through the air.

2. Drive smoothly

Tests showed frequent bursts of acceleration and braking reduced a Camry's mileage by 2 to 3 mpg. Once up to speed on the highway, maintain a steady pace in top gear. Smooth acceleration, cornering, and braking also extend the life of your car’s engine, transmission, brakes, and tires.

3. Reduce unnecessary drag

At highway speeds, more than 50 percent of engine power goes to overcoming aerodynamic drag. So don't carry things on top of your vehicle when you don't have to. Installing a large Thule Cascade 1700 car-top carrier on a Camry dropped gas mileage from 35 mpg to 29 at 65 mph.

4. Don't use premium fuel if you don't have to

If your car specifies regular fuel, don't buy premium under the mistaken belief that your engine will run better. The only difference you'll see is about 20 cents more per gallon. Most cars are designed to run on regular gasoline. Even many cars for which premium is recommended will run well on regular. Check your owner's manual to learn if your engine requires premium or if it runs on other grades.

5. Minimize driving with a cold engine

Engines run most efficiently when they're warm. In city-driving tests, making multiple short trips and starting the engine from cold each time reduced fuel economy by almost 4 mpg. Engines also produce more pollution and wear faster when they're cold. When possible, combine several short trips into one so that the engine stays warm.

6. Keep tires properly inflated

In Consumer Reports tests using a Camry, the car experienced a 1.3 mpg loss in highway fuel economy when the tires were underinflated by 10 psi. Underinflated tires also compromise handling and braking, and wear faster. Check the pressure of your vehicle's tires at least once a month with a tire gauge.

7. Avoid idling for long periods

When your car is idling, it’s getting zero miles per gallon. In the Consumer Reports study, when a Buick Lucerne with a V8 idled for 10 minutes warming up, it burned about an eighth of a gallon of gas. A smaller engine would probably burn less, but idling still adds up. Turn off the engine if you expect to sit for more than 30 seconds.

Bonus tips from Union Plus: 

• When you sign up for a year with the Union Plus Motor Club (cheaper than AAA), you can receive $40 in gas vouchers!
   
• And when your car needs service or new tires, use your union discounts.  With your Union Plus Goodyear Discount, you save 10% off Goodyear tires and 5%-10% off service. 
   
• Don't forget your Union Plus discount for ConsumerReports.org for more great advice on how to be a savvy consumer.
   
• Plus, check out these sites to enter a zip and find gas prices at stations near you:  GasBuddy, GasPriceWatch and AltFuelPrices.