Bespoke 280SE 4.5 Cabriolet


Bespoke 280SE 4.5 Cabriolet
An engineer’s 111

May 2013

Could it be possible that some of the rare Mercedes’ we covet are less than absolutely perfect? Dare we admit that we’re really not entirely happy with the way our oldtimer behaves after dropping an obscene amount of cash to buy it? Most MB enthusiasts cope with characteristics that are euphemistically regarded as their oldtimer’s ‘charm.’

As contemporary automobile technology has relentlessly marched forward, many of our cherished oldtimers fall farther behind the refinement of a new Ford Focus much less that of a new Mercedes of any description. Our oldtimers can begin to feel very, well…old! Savvy owners often re-engineer certain characteristics of their cars to correct what may have been acceptable 40 years ago but today mar the driving experience.

“While the purists will undoubtedly cringe, Mr. W’s creation would be our choice for the ultimate user-friendly 111 Cabriolet.”

Such an owner was a fellow we’ll just refer to as Mr. W. Mr. W is a highly educated and very technical fellow as well as a serious gearhead who fancied one of the gorgeous 111 cabriolets he’d admired as a younger man. His opportunity to own one came in 1983 when he purchased a tobacco brown (423) 1971 280SE 3.5 cabriolet trimmed cognac leather from its original California owner. The V8 111 Cabriolet had accumulated but 57k miles and was one of about 1,200 constructed.

Mr. W was (and still is at 90+ years today) a perceptive guy and the more he drove his new 3.5, the more the 3.5’s niggling quirks bothered him: 1st gear starts, irritating engine revs at 70mph and marginal cooling during 90 mph touring through the desert. Something had to be done and Mr. W. decided to get on with making his 3.5 a true grand tourer.


Is there a more attractive open 4 passenger Mercedes-Benz than the end of series V8, low grille, 280SE Cabriolet? This particular tobacco brown example will fool the casual observer.

Refining Mercedes’ masterpiece

Delivery of the 3.5 to Newport Beach, CA MB dealer Jim Slemons on November 30, 1983 began the car’s transformation. Mr. W had a list of “to-dos” that undoubtedly shocked the service personal: Replace the M116 3.5L engine with a new M117 4.5L liter engine, install a new limited slip 3.23 differential, install a new 4.5L 3-speed automatic transmission.

And he requested a larger capacity radiator that required relocating both the engine oil cooler and the trans cooler to the left and right front inner fender wells. And one final request was made: Slemons was instructed to strip the car to bare metal and respray it in the original tobacco brown once the mechanical upgrades were completed.

Mr. W. finally had the 3.5 Cabriolet he wanted in spring of 1984. The receipts are a fascinating read and reveal the driveline replacement and cooling upgrades consumed $19,269.76 and the respray a further $4593.89. And so an extraordinarily “one-off” 280SE 4.5 Cabriolet was created that erased most(all?) of the 3.5 Cabriolet’s inherent foibles. While the purists will undoubtedly cringe, Mr. W’s creation would be our choice for the ultimate user-friendly 111 Cabriolet.

How does it behave? The driving experience is sublime with an absence of intrusive engine noise, smooth up and downshifts and plenty of torque to pull the tall final drive ratio. Of course another 50 hp would be useful but difficult to achieve with period components. To Mr. W we say well done!


Sump guard and 4.5 badge betray this special 111 cabriolet’s underpinning. Upgrading to a M117 4.5 liter increased power by about 20 hp and raised the torque by a useful 47 ft/lb. Note the relocated engine oil cooler above the sway bar. Battery was relocated to the trunk!


Your author enjoying one silky smooth Cabriolet: the 280SE 4.5 edition!


roy spencer/editor mercedesheritage
photography/mercedesheritage – tim pinault

>Was this article interesting? Subscribe to our e-newsletter.

Leave a Reply