Opel Monza

Opel Monza: which version to buy and why

If you are choosing an Opel Monza, you are not choosing between generations: the catalogue lists 1 generation (1978–1986), Hatchback 3-door, 12 versions, all Gasoline, all RWD, all No boost, all with 140 mm ground clearance. The decision is which engine and gearbox pair to take. Power in the data runs from 100 hp (2.0 MT, 2.0 AT) to 180 hp (3.0 MT 180 hp).

If you are choosing an Opel Monza, you are not choosing between generations: the catalogue lists 1 generation (1978–1986), Hatchback 3-door, 12 versions, all Gasoline, all RWD, all No boost, all with 140 mm ground clearance. The decision is which engine and gearbox pair to take. Power in the data runs from 100 hp (2.0 MT, 2.0 AT) to 180 hp (3.0 MT 180 hp). That is 80 hp more at the top than at the bottom — 80% more peak power. Measured 0–100 km/h exists only for four manuals: 11 s (2.5 MT 130 hp), 10.5 s (2.5 MT 140 hp), 10 s (2.8 MT), 8.5 s (3.0 MT 180 hp). Fuel consumption (city, highway, combined), tank size, CO2, eco class and wheel size are not measured on every version.

Specs table: all 12 versions side by side

There is no second generation in the data, so nothing “changed between generations.” What changes is displacement (1979 → 2490 → 2784/2800 → 3000 cc), cylinder count (4 on both 2.0 versions, 6 on the rest), gearbox type (Manual vs Automatic), and, on the three 3.0 MT names, peak power (150, 156, 180 hp).

Power per litre: what extra displacement actually buys

Using hp ÷ (cc / 1000):

• 2.0 MT and 2.0 AT: 100 / 1.979 ≈ 50.5 hp/L
• 2.5 MT 130 hp and 2.5 AT 130 hp: 130 / 2.490 ≈ 52.2 hp/L
• 2.5 MT 140 hp and 2.5 AT 140 hp: 140 / 2.490 ≈ 56.2 hp/L
• 2.8 MT: 140 / 2.784 ≈ 50.3 hp/L
• 2.8 AT: 140 / 2.800 = 50.0 hp/L
• 3.0 MT 150 hp and 3.0 AT 150 hp: 150 / 3.000 = 50.0 hp/L
• 3.0 MT 156 hp: 156 / 3.000 = 52.0 hp/L
• 3.0 MT 180 hp: 180 / 3.000 = 60.0 hp/L

The densest engines in the catalogue are not the largest ones by default. 2.5 MT 140 hp at 56.2 hp/L beats 2.8 MT at 50.3 hp/L despite 294 cc less (2490 vs 2784). 3.0 MT 180 hp is the only version at 60.0 hp/L — 9.5 hp/L above 2.0 MT and 9.7 hp/L above 2.8 MT. Stepping from 2.0 MT (100 hp) to 2.5 MT 130 hp adds 30 hp for 511 cc more (+0.059 hp per extra cc). Stepping from 2.5 MT 130 hp to 2.5 MT 140 hp adds 10 hp with the same 2490 cc. Stepping from 2.5 MT 140 hp to 2.8 MT adds 0 hp for 294 cc more. Stepping from 2.8 MT (140 hp) to 3.0 MT 180 hp adds 40 hp for 216 cc more on the 2784 figure (+0.185 hp per extra cc).

If the question is “does a bigger number on the badge buy more power?”, the data say: only sometimes. 2.8 MT and 2.5 MT 140 hp share 140 hp / 103 kW. 2.8 AT is also 140 hp / 103 kW on 2800 cc.

Weight per horsepower (where kerb weight is measured)

Kerb weight is measured on four versions only; the other eight are not measured.

• 2.5 MT 130 hp: 1370 kg / 130 hp ≈ 10.54 kg/hp; gross 1900 kg
• 2.5 MT 140 hp: 1370 kg / 140 hp = 9.79 kg/hp; gross 1935 kg (35 kg more gross than the 130 hp twin, same 1370 kg kerb)
• 2.8 MT: 1375 kg / 140 hp ≈ 9.82 kg/hp; gross 1900 kg (5 kg more kerb than both 2.5 MT manuals, 35 kg less gross than 2.5 MT 140 hp)
• 3.0 MT 180 hp: 1370 kg / 180 hp ≈ 7.61 kg/hp; gross 1900 kg

3.0 MT 180 hp is 2.93 kg/hp lighter per horsepower than 2.5 MT 130 hp, with the same 1370 kg kerb. 2.5 MT 140 hp and 2.8 MT sit within 0.03 kg/hp of each other. 2.0 MT, 2.0 AT, both 2.5 AT, 2.8 AT, 3.0 MT 150 hp, 3.0 AT 150 hp and 3.0 MT 156 hp: kerb and gross not measured.

Payload implied where both masses exist: 2.5 MT 130 hp 530 kg (1900 − 1370); 2.5 MT 140 hp 565 kg (1935 − 1370); 2.8 MT 525 kg (1900 − 1375); 3.0 MT 180 hp 530 kg (1900 − 1370). Ground clearance is 140 mm on all 12. Tank and wheels: not measured on all 12.

Performance: the four measured sprints, and what is not measured

0–100 km/h and top speed exist only here:

• 2.5 MT 130 hp: 11 s, 195 km/h
• 2.5 MT 140 hp: 10.5 s, 202 km/h — 0.5 s quicker and 7 km/h higher than the 130 hp 2.5 MT
• 2.8 MT: 10 s, 195 km/h — 0.5 s quicker than 2.5 MT 140 hp, but 7 km/h slower on top speed
• 3.0 MT 180 hp: 8.5 s, 215 km/h — 2.5 s quicker than 2.5 MT 130 hp, 2.0 s quicker than 2.5 MT 140 hp, 1.5 s quicker than 2.8 MT; top speed 20 km/h above 2.5 MT 130 hp / 2.8 MT and 13 km/h above 2.5 MT 140 hp

City / highway / mixed consumption: not measured on all 12 versions. There is no mpg figure in the data to rank economy.

Torque where measured:

• 2.0 MT / 2.0 AT: 170 Nm at 3000 rpm
• 2.5 MT 130 hp: 186 Nm at 4600 rpm (+16 Nm vs 2.0, 1600 rpm later)
• 2.5 MT 140 hp / 2.5 AT 140 hp: 205 Nm at 4200 rpm (+19 Nm vs 130 hp 2.5 MT, 400 rpm earlier)
• 2.8 MT: 214 Nm at 3400 rpm (+9 Nm vs 140 hp 2.5, 800 rpm earlier than 4200)
• 3.0 MT 180 hp: 248 Nm at 4200 rpm (+34 Nm vs 2.8 MT, +78 Nm vs 2.0 MT)

2.5 AT 130 hp, 2.8 AT, 3.0 MT 150 hp, 3.0 AT 150 hp, 3.0 MT 156 hp: torque not measured. Peak power rpm: 5400 (both 2.0), 5300 (2.5 130 hp), 5200 (2.5 140 hp and 2.8 MT), 5800 (3.0 MT 180 hp); not measured on 2.8 AT, 3.0 MT 150 hp, 3.0 AT, 3.0 MT 156 hp.

Manual vs Automatic: what the extra ratio count is

Every Automatic in this generation is 3 speeds. Every Manual is 4 speeds except two: 3.0 MT 156 hp and 3.0 MT 180 hp are Manual 5.

Paired engines (same hp, different box):

• 2.0 MT vs 2.0 AT: both 100 hp, 170 Nm, 1979 cc, 4 Inline. Difference is Manual 4 vs Automatic 3. 0–100 and top speed not measured on both.
• 2.5 MT 130 hp vs 2.5 AT 130 hp: both 130 hp, 2490 cc, 6 Inline. The AT does not list torque, 0–100, top speed, compression, bore × stroke, fuel, valves per cylinder, engine position — those are not measured on 2.5 AT 130 hp. The MT lists them.
• 2.5 MT 140 hp vs 2.5 AT 140 hp: both 140 hp, 205 Nm at 4200, 2490 cc, fuel 95, Distributed injection (multi-point), Front, longitudinal, 2 valves per cylinder. 0–100 and top speed measured on the MT only (10.5 s, 202 km/h); AT: not measured. Kerb measured on the MT (1370 kg); AT: not measured.
• 2.8 MT vs 2.8 AT: both 140 hp. Displacement is 2784 cc on 2.8 MT and 2800 cc on 2.8 AT — not the same figure. Carburetor, 214 Nm, 10 s / 195 km/h, 1375 kg are on the MT; the AT leaves those not measured.
• 3.0 MT 150 hp vs 3.0 AT 150 hp: both 150 hp, 3000 cc, fuel 92, 6 Inline. Manual 4 vs Automatic 3. Performance, torque, kerb: not measured on both.

If you need a measured sprint, the data only support a Manual. If you need Automatic, you accept 3 speeds and, on most AT rows, missing 0–100 and top speed.

The 2.5 fork: 130 hp vs 140 hp (same name, different output)

Two 2.5 MT and two 2.5 AT share names. Separate them by power.

2.5 MT 140 hp vs 2.5 MT 130 hp: +10 hp (+7.7%), +19 Nm, peak power 100 rpm earlier (5200 vs 5300), peak torque 400 rpm earlier, 0.5 s quicker 0–100, +7 km/h top speed, same 1370 kg kerb, +35 kg gross (1935 vs 1900). Fuel 95 vs 92. Injection on the 140 hp MT is Distributed injection (multi-point); on the 130 hp MT the system is not measured. Compression 9.2 and bore × stroke 87 × 69.8 match. Engine position Front, longitudinal and 2 valves per cylinder match.

2.5 AT 140 hp vs 2.5 AT 130 hp: +10 hp. The 140 hp AT lists 205 Nm, fuel 95, Distributed injection (multi-point), Front, longitudinal, 2 valves per cylinder, compression 9.2, 87 × 69.8. The 130 hp AT leaves torque, fuel, injection, position, valves, compression and bore × stroke not measured.

2.5 MT 140 hp vs 2.8 MT: same 140 hp, different means

Both 140 hp / 103 kW at 5200 rpm, both Manual 4, both RWD, both fuel 95, both 6 Inline, 2 valves per cylinder, Front, longitudinal, No boost.

• Displacement: 2490 vs 2784 (+294 cc on 2.8 MT)
• Torque: 205 Nm at 4200 vs 214 Nm at 3400 (+9 Nm, 800 rpm earlier on 2.8 MT)
• Injection: Distributed injection (multi-point) vs Carburetor
• Compression: 9.2 vs 9.0
• Bore × stroke: 87 × 69.8 vs 92 × 69.8 (same stroke, 5 mm more bore on 2.8 MT)
• 0–100: 10.5 s vs 10 s
• Top speed: 202 km/h vs 195 km/h (7 km/h in favour of the smaller 2.5)
• Kerb: 1370 vs 1375 kg
• Gross: 1935 vs 1900 kg
• Specific output: 56.2 vs 50.3 hp/L

2.8 MT buys earlier and slightly higher torque and 0.5 s on 0–100. 2.5 MT 140 hp buys higher specific output and a higher measured top speed. Neither is “more powerful” in hp.

Three cars named 3.0 MT

• 3.0 MT 150 hp: 150 hp / 110 kW, Manual 4, fuel 92, 3000 cc. Torque, rpm, 0–100, top speed, kerb: not measured.
• 3.0 MT 156 hp: 156 hp / 115 kW (+6 hp vs 150 hp 3.0 MT), Manual 5 (the first 5-speed in the line-up as you climb power). Fuel 92. Torque, 0–100, top speed, kerb: not measured.
• 3.0 MT 180 hp: 180 hp / 132 kW (+24 hp vs 156, +30 hp vs 150), 248 Nm at 4200, Central injection (single-point or single- point), compression 9.4, 95 × 69.8, Front, longitudinal, 2 valves per cylinder, Manual 5, 8.5 s, 215 km/h, 1370 / 1900 kg, fuel 92.

From 3.0 MT 150 hp to 3.0 MT 180 hp is +30 hp (+20%) at the same 3000 cc. From 3.0 MT 156 hp to 3.0 MT 180 hp is +24 hp (+15.4%) and you keep 5 speeds. The 180 hp 3.0 MT is the only 3.0 with a measured sprint and the highest top speed in the file.

3.0 AT exists only at 150 hp — there is no 156 hp or 180 hp automatic in the data.

Chassis is not a differentiator

Front and rear suspension on all 12: Independent, spring. Front and rear brakes on all 12: Disc. Drive: RWD. Boost: No. Body: Hatchback 3-door. Years: 1978-01-01 to 1986-12-31 on every version. You cannot pick a Monza here for a different brake type, a different suspension type, or AWD: those options are not in the data.

Problems, reliability, mpg

The data do not list failure modes, reliability scores, or fuel use. City, highway and mixed consumption are not measured for every version. Any ranking of “which Monza is cheaper to run” from mpg is not supported here. What is supported is fuel grade where listed: 92 on 2.5 MT 130 hp and all three 3.0 manuals plus 3.0 AT; 95 on both 140 hp 2.5 versions and 2.8 MT. 2.0 MT, 2.0 AT, 2.5 AT 130 hp and 2.8 AT: fuel grade not measured.

Which version to choose

If you want the strongest measured performance: 3.0 MT 180 hp — 180 hp, 248 Nm, 8.5 s, 215 km/h, 7.61 kg/hp, 60.0 hp/L, Manual 5. That is 80 hp above 2.0 MT and 1.5–2.5 s quicker than the other measured manuals.

If you want 140 hp without the 3.0 badge: choose between 2.5 MT 140 hp (higher top speed 202 km/h, 56.2 hp/L, multi-point) and 2.8 MT (higher/earlier torque 214 Nm at 3400, 10 s 0–100, Carburetor). Same peak power.

If you want the smallest step up from 100 hp with a measured 0–100: 2.5 MT 130 hp — 130 hp, 11 s, 195 km/h, fuel 92, 10.54 kg/hp. +30 hp vs 2.0 MT.

If you need Automatic: 2.0 AT, 2.5 AT 130 hp, 2.5 AT 140 hp, 2.8 AT, or 3.0 AT 150 hp — all Automatic 3. The 140 hp 2.5 AT is the only AT with both 205 Nm and fuel 95 filled in. None of the automatics have a measured 0–100 in this file.

If you want a 5-speed but not 180 hp: 3.0 MT 156 hp is the only other Manual 5; 0–100 is not measured.

If you want the fewest cylinders and smallest displacement: 2.0 MT or 2.0 AT — 4 Inline, 1979 cc, 100 hp, 170 Nm. Performance and mass not measured.

If you want maximum listed power with a 4-speed: 3.0 MT 150 hp (150 hp, Manual 4). Do not confuse it with 3.0 MT 156 hp or 3.0 MT 180 hp.

Dimensions that do not help you pick: clearance 140 mm on all; tank not measured on all; wheels not measured on all. Prices are not in the data, so “what the extra money buys” here means what extra hp, Nm, seconds and kg the next row adds — not a currency amount.