NHTSA Rollover Resistance Ratings

The Vortec I-4's cylinder head features cast-alloy construction, dual overhead cams, and four valves per cylinder. The cams operate roller lobe followers that directly actuate the intake and exhaust valves. The four-valve-per-cylinder configuration is a true performance design - two small intake and exhaust valves can flow a greater quantity of air at a lower lift than can a single large intake and exhaust valve, and the four small valves are light in weight, which makes for accurate valve control. With the four-valve design, the spark plug is centrally located, which is an ideal position to ensure a complete ignition sequence.

The Vortec I-4's cylinder head features cast-alloy construction, dual overhead cams, and f

In the following chart, the Rollover Resistance Ratings of trucks are listed. Each truck is given a ranking of one to five stars, with five stars being the least likely to roll over. For comparison, we've also listed the Rollover Resistance Ratings of several popular automobiles, as supplied by the NHTSA. Each truck and SUV is listed as tested by the NHTSA, with body type (standard or extended cab), engine size and configuration, transmission type (manual or automatic), and tire size noted. The star ratings on the chart should be interpreted as such:

?????	=	HAS A RISK OF ROLLOVER OF LESS THAN 10 PERCENT
????	=	HAS A RISK OF ROLLOVER BETWEEN 10 AND 20 PERCENT
???	=	HAS A RISK OF ROLLOVER BETWEEN 20 AND 30 PERCENT
??	=	HAS A RISK OF ROLLOVER BETWEEN 30 AND 40 PERCENT
?	=	HAS A RISK OF ROLLOVER GREATER THAN 40 PERCENT

01 TrucksChevrolet S-Series, 2WD, extended cab, 4.3L V-6, automatic, 205/75R15: ???
Chevrolet S-Series, 4WD, extended cab, 4.3L V-6, automatic, 235/70R15: ???
Chevrolet Silverado, 2WD, extended cab, 4.8L V-8, automatic, 235/75R16: ????
Chevrolet Silverado, 4WD, extended cab, 4.8L V-8, automatic, 245/75R16: ????
Dodge Dakota, 2WD, Club Cab, 3.9L V-6, automatic, 215/75R15: ????
Dodge Dakota, 4WD, Club Cab, 4.7L V-8, automatic, 265/70R16: ???
Dodge Ram, 2WD, Club Cab, 5.2L V-8, automatic, 245/75R16: ???
Dodge Ram, 4WD, Club Cab, 5.2L V-8, automatic, 245/75R16: ???
Ford F-150, 2WD, standard cab, 4.2L V-6, automatic, 235/70R16: ???
Ford F-150, 4WD, standard cab, 4.2L V-6, automatic, 255/70R16: ??
Ford Ranger, 2WD, Super Cab, 4.0L V-6, automatic, 225/70R15: ???
Ford Ranger 4WD, Super Cab, 4.0L V-6, automatic, 245/75R16: ??
GMC Sierra: See Chevrolet Silverado ratings
GMC Sonoma: See Chevrolet S-Series ratings
Nissan Frontier, 2WD, crew cab, 3.3L V-6, five-speed manual, 255/65R16: ???
Nissan Frontier, 4WD, crew cab, 3.3L V-6, automatic, 265/70R16: ???
Toyota Tacoma, 4WD, crew cab, 3.4L V-6, automatic, 265/70R16: ??
Toyota Tundra, 4WD, extended cab, 4.7L V-8, automatic, 265/70R16: ???
Note: 2WD Toyota Tacoma and Tundra have yet to be rated by the NHTSA.

Select '01 SUVsChevrolet Blazer, 4WD, 4.3L V-6, automatic, 235/70R15: ??
Chevrolet Suburban, 4WD, 5.3L V-8, automatic, 265/70R16: ???
Chevrolet Tahoe, 4WD, 5.3L V-8, automatic, 265/70R16: ???
Dodge Durango, 4WD, 4.7L V-8, automatic, 265/70R16: ???
Ford Expedition, 4WD, 5.4L V-8, automatic, 255/70R16: ??
Ford Explorer, 4WD, 4.0L V-6, automatic, 235/75R15: ??
Jeep Cherokee, 4WD, 4.0L I-6, automatic, 225/75R15: ??
Jeep Grand Cherokee, 4WD, 4.0L I-6, automatic, 225/75R16: ??
Jeep Wrangler, 4WD, 4.0L I-6, five-speed manual, 225/75R15: ???
Nissan Pathfinder, 4WD, 3.5L V-6, automatic, 245/70R16: ???
Nissan Xterra, 4WD, 3.3L V-6, automatic, 265/70R16: ??
Toyota 4Runner, 4WD, 3.4L V-6, automatic, 265/70R16: ??

Select '02 SUVs
Chevrolet TrailBlazer, 4WD, 4.2L I-6, automatic, 245/70R16: ???
Ford Explorer, 4WD, 4.0L V-6, automatic, 235/70R16: ???
GMC Envoy: see Chevrolet TrailBlazer rating
Jeep Liberty, 4WD, 3.7L V-6, automatic, 215/75R16: ??

Select Automobile Ratings
Toyota Corolla, FWD, 1.8L I-4, automatic, 175/65R14: ????
Dodge Neon, FWD, 2.0L I-4, automatic, 185/65R14: ????
Honda Civic, FWD, 1.7L I-4, automatic, 185/65R15: ????
Ford Taurus, FWD, 3.0L V-6, automatic, 215/60R16: ????

Recall News: Jeep Grand Cherokee; Chevrolet TrailBlazer/GMC EnvoyDaimlerChrysler announced a recall of its Jeep Grand Cherokees, intended to repair faulty software that may cause the instrument panel to go dark. DaimlerChrysler reported there have been no accidents as a result of the darkened gauges and warning lamps and stated that the company's testing showed that the problem was unlikely to occur.

The General has its own recall to deal with. GM recalled 86,312 Chevy TrailBlazers and GMC Envoys (model-year '02) because of concerns that the vehicles could shift out of Park. "It could slip out of Park and the vehicle could roll, if the parking brake wasn't engaged," said GM spokesman Mike Morrissey. While the automaker hasn't received any reports about TrailBlazers or Envoys rolling while in Park, GM wanted to "make sure we don't have any experiences of this problem in the field."

General Motors stated the problem was due to a substandard part supplied by an outside manufacturer and installed in the GM-built transmission.