About the Mercedes-Benz 420
The Mercedes-Benz 420 SE, produced from 1985 to 1991, formed part of the legendary W126 S-Class generation. Powered by a smooth 4.2-litre V8 engine producing 224bhp, it combined effortless performance with exceptional build quality and advanced technology for its era. The long-wheelbase SEL variant offered additional rear legroom, making it a favoured choice for chauffeur-driven buyers.
Standard equipment included leather upholstery, electric seats, climate control, and ABS. Later models benefited from improved safety features and mechanical refinements. The 420 struck an ideal balance between the smaller-engined 300 SE and the flagship 560 SEL, offering strong performance with reasonable running costs for a car of this stature.
What Affects the Price of a Used Mercedes-Benz 420
Condition is paramount when valuing any W126 S-Class, with pristine, low-mileage examples commanding significant premiums. Full service history, particularly with Mercedes-Benz main dealer stamps, substantially increases value. Originality matters greatly to collectors, with unmolested cars featuring correct trim, wheels, and period specifications worth considerably more than modified examples.
Mileage has less impact than you might expect on these robust vehicles—a well-maintained 150,000-mile car often proves more valuable than a neglected 60,000-mile example. Colour combinations influence desirability, with classic shades like smoke silver, nautical blue, and black typically preferred. The SEL long-wheelbase variant generally commands £2,000-£5,000 more than the standard SE. Recent restoration work, new chrome, and documented mechanical refurbishment add significant value.
Buying Tips for the Mercedes-Benz 420
Inspect the bodywork thoroughly for rust in the rear wheelarches, sills, front wings, and around the windscreen. Check all electrical systems function correctly, as faults can be expensive to trace and repair. The wiring harness biodegrades on pre-1989 models, causing multiple electrical gremlins—budget £1,500-£2,000 for replacement if not already done.
Test the automatic transmission shifts smoothly through all gears without delay or harshness. Listen for timing chain rattle on cold starts, indicating wear that requires immediate attention. Examine the interior for worn seat bolsters, cracked dashboards, and faded wood trim. Verify air conditioning works, as regassing or compressor replacement proves costly. Always obtain a comprehensive pre-purchase inspection from a Mercedes specialist, and factor in maintenance costs of £1,500-£3,000 annually for a well-used example.