1970 Oldsmobile Cutlass SX A Supreme Enigma: eBay Find

When it comes to 1970 Oldsmobiles, collectors tend to favor performance models first, such as the 4-4-2, any F-85/Cutlass with the W31 package, and the Rallye 350. But what about the Cutlass SX? Most people are unfamiliar with this car, and even Oldsmobile folks are not sure what to make of it.

Basically, a Cutlass SX is a Cutlass Supreme hardtop or convertible with the Y79 SX package. Some websites (including this auction) claim that the SX package was an insurance-beater, but that’s not quite true. What’s closer to the truth is that the SX may have been in a similar vein to the Turnpike Cruiser from 1967-68. In 1967, the TC package included a 400ci motor, 2bbl. carburetor, TH400 automatic, and lazy gears for the Cutlass Supreme − the only non-4-4-2 to get the 400. For 1968, Oldsmobile redesigned its 400 and decided to offer the 2bbl. 400 on the 4-4-2 instead.

After skipping a year, the 2bbl. big-block − now a 455 − became part of the SX package for the Cutlass Supreme. Also included with the SX was the obligatory TH400, rear bumper with exhaust cut-outs (like the 4-4-2’s) with dual exhausts, special emblems, and other options not normally available on the Cutlass Supreme. The L33 455 was rated at 320 horsepower, but a L31 365-horsepower 4bbl. 455 became available. This was not a hi-po car at all, but at some point during the model year, Oldsmobile decided to cancel the 455-2 and make the 455-4 standard. In addition, it released the W32 motor, which was the same motor that was standard on the 4-4-2, also rated at 365 horsepower − the same as the other 455. According to an Oldsmobile Marketing Department Bulletin dated 2-24-70:

While the description of the L31 and the W32 engines (for the SX Performance Package) are similar, there is considerable difference in engine characteristics. The L31 engine is designed to operate with lower axle ratios (2.56, 2.78, or 3.08) and develops maximum torque at lower r.p.m. Option W32 is a performance engine designed to operate with higher axle ratios (3.08, 3.23, or 3.42) and develops maximum torque at higher r.p.m.

In other words, the Cutlass SX was a smooth highway cruiser that offered a great combination of performance and economy, but if you ordered the W32 motor, you had Oldsmobile’s version of the Monte Carlo SS 454 and the Pontiac Grand Prix, both cars that were a bit more personal-luxury yet offered substantial power.

Production for 1970 totaled 7,197 split between 6,404 hardtops and 793 convertibles. The SX package returned for one more year, but it was only available with the mild 455-4, now with low compression. Only 2,177 were built, with 1,820 hardtops and 357 convertibles built.

This Cutlass SX convertible on eBay comes with the standard 455-2 motor and is claimed to be an original California car, although it subsequently resided in Florida and Michigan. The odometer shows 54,000 miles, which are undocumented but the seller says it drives like a car with those low miles. Other features include a repaint, bench seat, column automatic, AC, power windows, power top, power steering and brakes, and AM/FM 8-track. Want a good driver without breaking the bank for a 4-4-2 W-30? Right now this Cutlass SX convertible is at $17,900 without meeting reserve.