To satisfy its demanding customers, Ford Motor Co. made development of its all-new I-4 engine family - with displacements of 1.8L, 2L and 2.3L - an exercise in give and take.

The No. 2 automaker is giving in to its core customers - Ranger pickup fans - while hoping others aren't taken aback.

Referring to Ranger's new base engine, the Dearborn-built 2.3L, I-4 program manager Joe Pratt boasts: "The outgoing engine that we're replacing is 119 hp. We're 130 hp. And at equivalent torque." But, he adds, there is a price to pay for "low-end grunt."

Compared to its predecessor - the aged 2.5L OHV I-4 - the new 2.3L unit makes a 0-to-60 mph (0-to-97 km/h) trip about 2.5 seconds quicker.

Thanks, in no small part, to the I-4's aluminum block and aluminum alloy cylinder head. The old engine's cast-iron block/head makes it more than 70 lbs. (32 kg) heavier.

The '01 Ranger equipped with the new 2.3L DOHC I-4 was supposed to roll off the line late last year, but Mr. Pratt dismisses the delay.

"It had nothing to do with the engine," he says, assigning blame to "NVH concerns."

The Ranger equipped with the new I-4 will be in showrooms this month.

This engine family was designed, say insiders, before Ford's much-publicized corporate mandate to raise the fuel economy of its trucks and sport/utility vehicles upwards of 25% by 2005. Part of that strategy is based on new engine architectures featuring three valves per cylinder - which the new I-4 family doesn't have. Not known is whether this family will be redesigned or ditched entirely in favor of a new 3-valve design.

In addition to Dearborn, the all-new I-4s are made at Ford's Chihuahua, Mexico, plant (for Ford of Europe's popular Mondeo); and beginning in 2003, a third plant - under construction in Valencia, Spain - also will manufacture the I-4. In addition, I-4s will be made for Mazda at a plant in Hiroshima, Japan, Mr. Pratt says, adding that the Japanese automaker had significant input in the I-4's development.

When all four plants are running, annual production is expected to approach 2.2 milllion units. And each plant can manufacture any and all variations of the engine.

The I-4 program also featured development of a 2.8L 5-cyl. engine. But it's on hold until a customer can be found. Volvo, acquired by Ford in 1999, makes extensive use of its own 5-cyl. engine, but Mr. Pratt doubts it threatens the future of Ford's I-5.

"There's been a lot of discussion about how to marry their engine family to our engine family. They have some platform constraints because of their vehicles. And we have some other constraints. It's safe to say they'll probably both continue."