As gasoline prices continue to rise, installations of thrifty 4-cyl. engines have trended upward, larger mills have become scarcer and Chrysler LLC is tracking ahead on all fronts, according to Ward's data.

Among '07 passenger cars assembled in North America and sold in the U.S. through January, 4-cyl. engines were the most popular, accounting for 50.6%, or 1.7 million units of production through January. That compares with 2.8 million units, or 48.5%, for the entire '06 model year.

Chrysler ranks as the biggest booster, buoyed by wider availability of 4-cyl. engines. The auto maker features the economical mills in five model lines this year compared with one in 2006.

Through January, Chrysler built 83,008 '07 cars with 4-cyl. engines, or 42.5% of its total passenger-car run. That is well ahead of the 18.1% installation rate for the entire '06 production run, when 92,478 engine bays were filled with 4-cyls.

On the volume side, however, the Detroit Three remain well behind their Japanese rivals. Toyota Motor Engineering & Mfg. USA led the way, installing 4-cyl. engines in 516,052 of the passenger cars it assembled in North America. That represents 81.5% of its '07-model production through January. For the entire '06 model year, Toyota's installation rate was 80.1%.

Honda of America Mfg. Inc. was next with 422,108 4-cyls., or 78.2%, up from 76.4% for '06.

Meanwhile, General Motors Corp. is on course to record an increase to 35.3% from 33.5%, but its volume ranked third with 303,524 units.

Ford Motor Co. also saw an increase. Its 197,106 4-cyl. cars represent a 30.7% installation rate, compared with 25.4% for the '06 production run.

Meanwhile, 8-cyl. engines were installed in 240,945 North American-made passenger cars, or about 7.1% of '07 domestic car production, through January. That compares with 596,449 units, or roughly 10.2% of all domestic passenger-car production, for the full '06 model-year.

Ford accounted for the largest share of 8-cyl. installations, with 131,820 units, or 20.5% of its '07 passenger-car production. The Ford Mustang grabbed more than one-third of the installations.

Chrysler used 8-cyl. engines in 27,342 of its cars for 14% of its passenger-car total, while GM installed 8-cyl. mills in 81,783 units for 9.5% of its passenger-car total.

Installations of V-8s are down most sharply at Chrysler, which has trimmed 8-cyl. use in passenger cars by roughly half. Ironically, Chrysler also lays claim to what is arguably the best-known 8-cyl. engine on the market — the Hemi. However, take-rates have slipped as gasoline prices have risen.

Hemi take-rates were well above 60% when the engine first launched in 2004. And they declined more slowly, hovering near 50%, than the industry norm for a new product.

They now stand at about 37%, Chrysler says. Gasoline prices have spiked in spring every year, since 2005. All-time highs have been recorded twice during that period.

And like the 8-cyl. mills, installations of 6-cyl. engines are trending downward, Ward's data reveals. Through the initial months of '07 production, auto makers installed 6-cyls. in 36.8% of all domestically produced passenger cars, or 1.3 million units.

That compares with 2.3 million units, or 38.8% of all '06 passenger-car production.

Among Detroit-based auto makers, Chrysler leads the pullback, installing 6-cyl. mills in 43.5% of its '07 production versus 53.2% for all of model-year '06. GM, Ford, and Toyota have cut use of the architecture more modestly.

The light-truck story is slightly different. Through January, 8-cyl. engine installations stood at 1.7 million units, or 44.8% of all light truck production through January.

That's up slightly from the 3.2 million, or 41.6% of trucks that carried an 8-cyl. mill for the entire '06 model year.

GM has driven that growth, supplying the architecture to 957,332 units, or 61.1% of its '07 trucks, compared with 1.2 million units, or 49.6% of its truck mix for all of '06.

Ford trimmed its 8-cyl. truck installations to 54.4% from 63.2%. And the same holds true with Chrysler, which saw a reduction to 22.6% from 26.5%.

In a trend that reflects the soft sales of its first fullsize pickup, Toyota installed 8-cyl. engines in 61,636 Tundras for a rate of 21.4%. The last model-year of the previous-generation Tundra saw 152,510 8-cyl. installations for a 24.6% rate.

Nissan North America Inc. also is tracking a decline in 8-cyl. installations. Through January, 29.8% of '07 Nissan trucks featured 8-cyl. mills, down from 34.1% for '06.

Engine Installations on '07 Model Domestic Light Trucks

(2007 model year output through January 2007)
Industry Total % Total
Total 4-Cyl. Engines 382,488 10.4
Total 5-Cyl. Engines 66,923 1.8
Total 6-Cyl. Engines 1,571,990 42.6
Total V-8 Engines 1,653,677 44.8
Total Truck Output 3,691,007

Engine Installations on '07 Model Domestic Cars

(2007 model year output through January 2007)
Industry Total % Total
Total 4-Cyl. Engines 1,712,635 50.2
Total 5-Cyl. Engines 188,290 5.5
Total 6-Cyl. Engines 1,255,959 36.8
Total V-8 Engines 240,945 7.1
Total Car Output 3,414,336
Source: WardsAuto.com