First Test: 2004 Isuzu Axiom Direct Injection

Not only are emissions lower and fuel economy higher, but horsepower and torque are increased--by nearly 10 percent .

Allyson Harwood
Jun 8, 2004
Photographers: The Manufacturer
For 2004, Isuzu's modern-looking Axiom gets a 3.5-liter direction-injection gasoline engine as standard equipment. Not only is this the first direct-injection powerplant Isuzu has brought to America, but is also the only D.I. gas engine you can get here for under $100,000.

The new engine generates more power, has better fuel economy, and can run on regular unleaded gas, all while putting out lower emissions (the Axiom D.I. is a LEV II vehicle) than a comparable traditional fuel-injected engine. With direct injection, each injector is located in the combustion chamber, as opposed to the standard location in the intake port. This affords an efficient use of the fuel--it's sprayed at a high pressure, allowing more gas to be used in combustion. Direct injection has precise fuel metering, which makes the best use of the gas. Also improving this engine's operation is variable valve timing.
Not only are emissions lower and fuel economy higher, but horsepower and torque are increased--by nearly 10 percent in both cases. This engine can run at a higher compression ratio (10.3:1, as opposed to 9.1:1) on regular unleaded, making more power without engine knock. This sport/utility is a real fire-breather: Compared to TT's test numbers on the standard Axiom, the Axiom D.I.'s 0-60 and quarter-mile times are down by a full second each. A vehicle that gives better mileage, reduced emissions, and more power sounds too good to be true, but it's real and is currently on the market. Behind the wheel, you know this isn't a typical fuel-injected engine as soon as you hear the diesel-like noise it makes in cold starts.
The only problem is that the technology is limited to the not-too-popular Isuzu brand: This engine is standard on the Axiom and optional on the '04 Rodeo. Our guess is this technology will spread (we're hearing possibly to GM models), but it certainly won't be the salvation of the struggling import-SUV manufacturer. Nevertheless, this is impressive technology on every front (as well as at the start line) at a solid entry-level price.
Photo 2/5   |   2004 Isuzu Axiom Direct Injection Front View
Photo 3/5   |   2004 Isuzu Axiom Direct Injection Front Drivers Side View

Photo 4/5   |   2004 Isuzu Axiom Direct Injection Interior View
Photo 5/5   |   2004 Isuzu Axiom Direct Injection Rear Drivers Side View



Subscribe Today and Save up to 83%!

Subscribe Truck Trend Magazine

Subscribe to:

Truck Trend

Subscribe Diesel Power Magazine

Subscribe to:

Diesel Power

Subscribe Truckin Magazine

Subscribe to: