With my 4WD 2004 Nissan Titan rolling past the 15,000-mile mark, I've logged few complaints. The engine's rock solid and the suspension is as tight as the day I drove it off the lot.
One potential negative I overlooked was fuel consumption (EPA city/highway was listed as 14/18 mpg). When I bought the truck in 2004, the price of gas in my neighborhood was $1.43 per gallon. Two years and a dollar more per gallon later, my beauty is an insatiable beast with its 305-horsepower, 5.6-liter V-8 gulping the precious fluid. Averaging roughly 10.5 mpg in suburban driving, my love for the big truck began to wane. The Titan had become an extra mouth to feed. So, like the millions of other Americans who struggle to make ends meet, I had to reduce fuel consumption.
The first step toward better fuel economy was to dramatically change my driving habits. But easing my lead foot yielded minute results--a mere increase of 0.5 mpg.
The next move was to switch to 91 octane fuel. Oddly, there wasn't a significant increase in mileage with high-test, but there was a slight boost in power, which translated into quicker acceleration. This made me recall a question automotive gurus have been asking since the oil crisis of the 1970s: Can the addition of power combined with the restraint not to use it increase fuel economy?
Installing a product that Nissan offers could help me find the answer. A cold-air intake, designed by NISMO, Nissan's motorsports division, is said to bump horsepower in the Titan and Armada. The NISMO R-tune cold-air intake claims gains of 12.5 horsepower at 5500 rpm. And, while other cold-air intake manufacturers claim power and fuel-economy increases, Dean Case, Nissan's manager of technology and special topics, explains, "The cold-air intake has never been tested for improved fuel economy. It's strictly a performance enhancer for enthusiasts." But when pressed on the theoretical probability of using the intake as a fuel-economy measure, he conceded, "If you chose not to use the extra power, it could translate into improved fuel economy."
When gasoline hit $3.19 a gallon after Hurricane Katrina, I decided to try the experiment and had the NISMO intake installed by a certified Nissan tech, who also replaced the engine oil with a synthetic blend to reduce friction. I also inflated the tires beyond the manufacturer's recommended air pressure (up from 35 psi to 38) to see if it would make a difference.
To my amazement, the truck's driving characteristics changed immediately. A noticeable boost in horsepower made the vehicle seem lighter and quicker to respond. After blasting around town (frightening innocent motorists who were reluctant to let me merge) with this fantastic roar and surge of power, I refilled the tank and resumed more sensible testing. The initial results were promising: 11.5 mpg in the city in the first 150 miles of testing.
However, the early arrival of winter in the Northeast and dramatic drop in ambient outdoor temperature resulted in a corresponding drop in fuel economy. The overall test yielded an underwhelming 10.7 mpg city, 13.7 mpg overall.
The bottom line? If you crave more power, cold-air intakes deliver. The NISMO R-tune intake certainly boosted available horsepower. But if you're after improved fuel economy, you're better served easing off the accelerator and using that $300 cash on gas.