What Is the Difference Between VIN 3 & VIN C in a 1988 Delta 88 Royal Brougham?

The 1988 Oldsmobile Delta 88 Royale Brougham has a 3.8-liter, 231-cubic-inch displacement (cid) V-6 MFI engine with two VIN options: "3" and "C," which refer to the eighth character of the vehicle identification number. Almost all references to this car differentiate between the two. However, reasons for the distinction remain difficult to find. The MFI designation means "multiport fuel injection," which all the engines have.

The VIN

Every vehicle manufactured since 1981 has a 17-character, alphanumeric vehicle identification number. The first three characters identify the country, manufacturer and make. The next five characters tell information about the car itself, but the manufacturer creates specific character designations that may change from year to year. The ninth character prevents against fraud; the 10th identifies the year; the 11th, the manufacturing plant and the remaining characters form a unique serial number.

History

For the 1984 and 1985 Royale Broughams, the eighth character in the VIN represents different engine sizes: the letter "A" for a 3.8-liter V-6 engine with a two-barrel carburetor; "Y" for a 5.0-liter V-8 engine with a four-barrel carburetor; and "N" for a 5.7-liter diesel engine. In 1986 and 1987, the number "3" appeared with the 3.8-liter V-6 engine having multi-port fuel injection.

The Change

In 1988, Oldsmobile modified the 3.8-liter engine to improve its performance and efficiency, and changed the VIN designation to "C" for the new model. But it was still basically identified as a "3.8L 231cid V6 MFI (VIN 3 or C) OHV" engine. Oldsmobile sold several Royale Broughams that year with either engine. To the purchaser, there was no apparent difference other than the VIN. The "3" designation disappeared in 1989.

The Differences

The differences appear in the technical specifications of some of the engine parts. For example, for the "3" model, the exhaust valves have a 1.5 -nch head diameter, a 0.3408-inch stem diameter and a 4.718-inch overall length (O.A.L.). The "C" valves have 1.487-inch head diameter, a 0.3555-inch stem diameter and a 4.727-inch O.A.L.

Similarities

Some engine parts remain the same, such as camshaft and connecting rod bearings. You can see more technical similarities and differences by comparing engine part specifications. For example, on the Rock Auto website (see References), click on "Start" to open the parts catalog, then click on "Oldsmobile," "1988," "Delta 88 Royale Brougham," click on the "3" or "C" options and click on various engine parts for each and compare the specifications.