Oldsmobile Omega: Which Version Should You Buy?

Choosing an Oldsmobile Omega from the catalogue data comes down to two very different formulas. The 1975–1979 generation is a Sedan with two Gasoline, Automatic, RWD versions: 4.1 AT and 5.0 AT.

Choosing an Oldsmobile Omega from the catalogue data comes down to two very different formulas. The 1975–1979 generation is a Sedan with two Gasoline, Automatic, RWD versions: 4.1 AT and 5.0 AT. The 1980–1984 generation is also a Sedan, but its six listed versions use FWD and offer Manual or Automatic gearboxes, with either a 2.5-litre Inline four-cylinder engine or a 2.8-litre V-shaped six-cylinder engine. For buyers who prioritize measured performance, the 1980–1984 2.8 MT with 112 hp provides the strongest documented result: 0–100 km/h in 10.9 seconds and a top speed of 175 km/h. The 135 hp versions offer the highest stated output, but their acceleration and top-speed figures are not measured.

Oldsmobile Omega generations: what changed?

The 1975–1979 Oldsmobile Omega generation contains two versions, both with a Sedan body. The 4.1 AT has a 4,090 cm³ Gasoline engine with 6 cylinders in an Inline layout, while the 5.0 AT has a 5,001 cm³ Gasoline engine with 8 cylinders in a V-shaped layout. Both engines are mounted Front, longitudinal and paired with Automatic transmission and RWD. Power, torque and gearbox gear counts are not measured, so the available data cannot establish which of these versions is faster or more powerful.

The 1980–1984 Oldsmobile Omega generation contains six versions and retains the Sedan body while changing the mechanical specification to FWD. Buyers can choose a 2.5 MT or 2.5 AT with a 2,471 cm³ Inline four-cylinder engine, or a 2.8 MT or 2.8 AT with a 2,835 cm³ V-shaped six-cylinder engine. The 2.8 versions appear with either 112 hp or 135 hp, so identical version names must be distinguished by output. Manual versions have 4 gears, while Automatic versions have 3 gears.

Oldsmobile Omega engine options and specs

GenerationVersionPowerTorqueDisplacementFuelCylindersLayoutBoostGearboxDrive
1975–19795.0 ATnot measurednot measured5,001 cm³Gasoline8V-shapednot measuredAutomatic, gears not measuredRWD
1975–19794.1 ATnot measurednot measured4,090 cm³Gasoline6Inlinenot measuredAutomatic, gears not measuredRWD
1980–19842.5 MT91 hp / 67 kW182 Nm2,471 cm³Gasoline4InlineNoManual, 4 gearsFWD
1980–19842.5 AT91 hp / 67 kW182 Nm2,471 cm³Gasoline4InlineNoAutomatic, 3 gearsFWD
1980–19842.8 MT (112 hp)112 hp / 82 kW197 Nm2,835 cm³Gasoline6V-shapedNoManual, 4 gearsFWD
1980–19842.8 AT (112 hp)112 hp / 82 kW197 Nm2,835 cm³Gasoline6V-shapedNoAutomatic, 3 gearsFWD
1980–19842.8 MT (135 hp)135 hp / 99 kW197 Nm2,835 cm³Gasoline6V-shapedNoManual, 4 gearsFWD
1980–19842.8 AT (135 hp)135 hp / 99 kW197 Nm2,835 cm³Gasoline6V-shapedNoAutomatic, 3 gearsFWD

Within the 1980–1984 generation, moving from either 2.5 version to a 112 hp 2.8 version adds 21 hp, 15 Nm and 364 cm³. The 112 hp 2.8 engine produces approximately 39.5 hp per litre, compared with approximately 36.8 hp per litre for the 91 hp 2.5 engine.

The 135 hp 2.8 versions add 23 hp over the 112 hp 2.8 versions while displacement remains 2,835 cm³ and stated torque remains 197 Nm. Their specific output is approximately 47.6 hp per litre, about 8.1 hp per litre higher than that of the 112 hp 2.8. This makes the 135 hp specification the strongest choice by stated power density, although the data does not show whether that advantage produces better measured acceleration.

Fuel delivery also separates the engines. The 1980–1984 2.5 MT and 2.5 AT use Central injection (single-point or single- point), whereas all four 2.8 versions use Carburetor. The fuel systems of the 1975–1979 4.1 AT and 5.0 AT are not measured.

Performance, acceleration and mpg

GenerationVersion0–100 km/hTop speedCity consumptionHighway consumptionCombined consumption
1975–19795.0 ATnot measurednot measurednot measurednot measurednot measured
1975–19794.1 ATnot measurednot measurednot measurednot measurednot measured
1980–19842.5 MT13.1 s165 km/hnot measurednot measurednot measured
1980–19842.5 AT15.5 s158 km/hnot measurednot measurednot measured
1980–19842.8 MT (112 hp)10.9 s175 km/hnot measurednot measurednot measured
1980–19842.8 AT (112 hp)12.5 s173 km/hnot measurednot measurednot measured
1980–19842.8 MT (135 hp)not measurednot measurednot measurednot measurednot measured
1980–19842.8 AT (135 hp)not measurednot measurednot measurednot measurednot measured

The transmission comparison is clearest in the 91 hp 2.5 pair. The 2.5 MT reaches 100 km/h 2.4 seconds sooner than the 2.5 AT and has a top speed 7 km/h higher. Both have the same 2,471 cm³ engine, 91 hp and 182 Nm, making the Manual gearbox the stronger documented performance choice.

The same pattern appears in the 112 hp 2.8 pair. The 2.8 MT reaches 100 km/h 1.6 seconds sooner than the 2.8 AT, while its top speed is 2 km/h higher. Compared with the 2.5 MT, the 112 hp 2.8 MT is 2.2 seconds quicker to 100 km/h and 10 km/h faster at the top end. Compared with the 2.5 AT, the 112 hp 2.8 AT is 3.0 seconds quicker and 15 km/h faster.

No city, highway or combined fuel-consumption figure is measured for any listed Oldsmobile Omega version. An mpg comparison therefore cannot be made from the available data. The 1975–1979 versions specify fuel as 92, while the fuel grade for every 1980–1984 version is not measured.

Oldsmobile Omega dimensions, weight and practical specs

GenerationVersionKerb weightGross weightGround clearanceTankWheel sizes
1975–19795.0 ATnot measurednot measurednot measurednot measurednot measured
1975–19794.1 ATnot measurednot measurednot measurednot measurednot measured
1980–19842.5 MTnot measurednot measured193 mmnot measurednot measured
1980–19842.5 ATnot measurednot measured193 mmnot measurednot measured
1980–19842.8 MT (112 hp)not measurednot measured193 mmnot measurednot measured
1980–19842.8 AT (112 hp)not measurednot measured193 mmnot measurednot measured
1980–19842.8 MT (135 hp)not measurednot measured193 mmnot measurednot measured
1980–19842.8 AT (135 hp)not measurednot measured193 mmnot measurednot measured

Kerb weight and gross weight are not measured for any version, so weight per horsepower cannot be calculated. Tank capacity and wheel sizes are also not measured throughout the range. Ground clearance is measured only for the 1980–1984 generation, where every version has 193 mm.

All listed versions use Independent, spring front suspension and Dependent, spring rear suspension. Every version also combines Disc front brakes with Drum rear brakes, so these items do not provide a basis for choosing between engines or transmissions.

Oldsmobile Omega reliability and problems

Reliability, maintenance history and known-problem data are not measured for any version. The specifications therefore cannot support a claim that the 4.1 AT, 5.0 AT, 2.5 MT, 2.5 AT, either 2.8 MT, or either 2.8 AT is more reliable. A buying decision based on problems or durability requires information beyond this catalogue dataset.

Which Oldsmobile Omega version should you buy?

For the best fully measured performance, choose the 1980–1984 2.8 MT with 112 hp. Its 10.9-second 0–100 km/h result and 175 km/h top speed are the best measured figures in the data, and it improves on the 2.5 MT by 21 hp and 15 Nm.

For an Automatic with measured performance, the 1980–1984 2.8 AT with 112 hp is the strongest documented choice. It reaches 100 km/h in 12.5 seconds and has a 173 km/h top speed, outperforming the 2.5 AT by 3.0 seconds and 15 km/h.

For maximum stated output, choose the 1980–1984 2.8 MT or 2.8 AT with 135 hp. Each delivers 23 hp more than its 112 hp counterpart from the same 2,835 cm³ displacement, but neither has measured acceleration or top speed. The Manual version offers 4 gears, while the Automatic has 3.

Choose the 2.5 MT over the 2.5 AT when documented performance matters: their power and torque are identical, but the 2.5 MT is quicker to 100 km/h and has the higher top speed. Choose the 1975–1979 4.1 AT or 5.0 AT only when the earlier generation’s Automatic, RWD configuration is the priority. Between those two, displacement and engine layout are known, but power, torque, acceleration and top speed are not measured, so the data does not justify naming either one the better performer.