Buying a used Mercedes-Benz SL (1971-1989)

By 1970 the car-making world was beholden to the massive US market. If you wanted to sell prestige cars in America you needed a sporty 'flagship' model that would bring aspirational buyers to your range.

Mercedes-Benz had done well worldwide with its pretty 230-280SL ‘Pagoda’ sports cars but they were never going to challenge performance models like the Porsche 911, Jaguar E-Type or the USA's own Chevrolet Corvette.

In response came the R107 Series with 3.5 and 4.5-litre V8 engines, short or long-wheelbase versions and a look of determined opulence. This was most definitely a conservative design but that attribute would help derivatives remain in production for longer than any Mercedes-Benz series.

The 350SL roadster made its Australian appearance in 1971. At $15,400 it was slightly cheaper than the four-door 350SE sedan but a whopping $5000 less than the long-wheelbase 350SLC coupe version.

Cars for Australian consumption were delivered with factory air-conditioning and power steering but SL owners missed out on the SLC's electric windows and everyone was expected to manually adjust the seats. A hefty addition to the options list was the removable SL hardtop which came with a special storage frame.

Buyers who chose the bigger-engined 450SL would have struggled to notice any performance advantage. That's because there was none. All of the bigger engine's potential for more power was sapped by various emission-control measures, leaving it rated at exactly the same 147KW as the 3.5.

Long-wheelbase SLC versions sold into our market were always automatic and often loaded with pricey extras like leather trim and an electric sunroof. The back seat wasn't spacious at all, however well-heeled parents could strap their younger offspring into that reasonably confined space knowing they were about as safe then as anyone could be in a four-wheeled conveyance.

Massive price increases saw the cost of an SL treble between 1973 and 1980 yet there seemed no end to the queue of customers. Helping justify continually increasing cost was wood-grain dash trim across the range from 1976 and electric windows in open-top cars from 1979.

Late in 1980 came the SL that most people today want to own. The 3.8-litre 380 model delivered slightly less power, but its modern aluminium V8 was hooked to four-speed automatic transmission, prompting faster response and better fuel economy than the ageing 4.5-litre.

The most powerful 107 Series arrived here in 1986 in the shape of the 560 and at $143,000 cost more than a nice capital city home. By 1989 and with enhanced safety and other equipment included, the 560’s price-tag exceeded $183,000.

Despite a significant increase to engine capacity, output climbed to just 175kW. However there was a significant 30 per cent gain in torque.

Benz didn't build an SLC version of the 560SL, instead relying on its megalithic SEC to deal with buyer demand for a big-engined coupe.

On the road in a used Mercedes-Benz SL (107 Series)

If you think that these lumps of Germanic luxury might be carved from a single billet of Krupp steel, a drive that takes in some coarse and bumpy bitumen may confirm your suspicions. While some prestige models of similar age rattle and bang in roughish going, an SL with its suspension in good working order will provide a firm but well-controlled ride.

Some people are implacable devotees of MB-Tex upholstery, while others describe the seats as resembling a very expensive park bench. Maybe Mercedes didn't want its drivers dozing off on the long journeys which to an SL or SLC are second nature. Ensure your test drive gives you enough seat time to make an informed judgement.

Once up to cruising speed, even the smallest engined SLs generate minimal stress at speeds legal only on an autobahn and deal easily with the lumps, bumps and corrugations of Australian back-roads.

No surprise therefore that these cars were highly regarded in long-distance rallying where toughness and the ability to sustain high speeds in appalling conditions saw them occasionally win and frequently appear on the podium at events conducted in the wilds of Africa and South America.

Handling, with dual wishbones and (in early versions) swing-axles at the rear, is excellent and doesn't deteriorate just because road conditions do. Wet conditions require caution, mainly because of tyre deterioration. Tyres showing plentiful tread may be age-hardened and not gripping at all.

The power steering should feel firm and direct with minimal 'slop'. Yes, the front wheels are meant to lean when turning tightly.

Some drivers are adept at manually controlling the M-B automatic transmission via its 'dog leg' shifter but most will just lean on the fairly hefty throttle pedal and let the transmission sort itself out.

Performance, considering the weight an SL typically carries, is fair enough; 0-100km/h for a two-seater in around 9sec with the heftier SLC a second slower.

The 380SLs were the first of the series to offer antilock brakes (ABS) and these systems are now getting a bit ancient as well. Where safe to do so, brake sharply to see if the ABS system is still operational.

Safety issues have to be considered in the comparison with other vehicles of similar age, not the standards of today. The brand pioneered crumple zones and 560SLs were among the first with driver and passenger airbags.

While prices for most older Mercedes models have collapsed and appear unlikely to recover, SL versions have held their values extremely well. Looking at the 560SL, at least, there is even some possibly sustainable value growth occurring.

The ancient saying; 'If you need to ask about fuel consumption you can't afford the car' certainly rings true for V8-engined SLs but fuel cost is a lot less relevant than when these cars were new.

Most are now owned purely for recreation and lucky to now get anywhere near the annual distance limits permitted by specialist insurers. Full-rate registration on a V8 in some places can exceed $1000 annually, however, V8-engined SLs do qualify for Concessional (Club) registration.

Check points
>> Once you decide on a car, engage a specialist Mercedes-Benz technician to provide a pre-purchase report. Problems that seem trivial can cost significant sums to rectify.

>> Cylinder-head cracks and warping were common and often due to poor maintenance and overheating. Those issues will be less prevalent now that cars aren't exposed to the grind of commuter traffic. Still look for contaminated 'milky' oil under the filler cap and oily scum in coolant.

>> Cars that have survived 40+ years will most likely have been treated to some body repairs and at least one respray. Expert inspection will identify structural problems but before spending money, check sills and wheel-arches, metal adjacent to the headlights, the boot lip and ahead of the windscreen. Rust in these areas or obvious repairs indicate a car to avoid. Lift the doors to check for hinge wear and look at headlight covers for cracks.

>> If the front end rattles and steering feels disconnected or notchy look for power steering leaks, collapsed bushings and inner-edge tyre wear. Suspension or steering issues aren't insurmountable but do influence the purchase price.

>> Neglected-fuel injection systems can cause problems including fires, so be wary of a car that blows black smoke, is hard to start from warm or smells of petrol.

>> When inspecting a car with a hardtop, insist that the vendor removes and refits it. This ensures you know it hasn't been sealed to the car to prevent water entry. While the top is off, erect the soft-top (if there is one) to check for damage to the fabric or frame.

carsales used vehicle ratings Mercedes-Benz SL (107 Series)
Design & Function: 15/20
Safety: 14/20
Practicality: 10/20
Value for Money: 12/20
Wow Factor 15/20 (560SL)
TOTAL SCORE: 66/100

Also Consider: Porsche 911SC, Jaguar XJS, BMW 635CSi