Is the Mercedes Benz R129 SL a future classic?

Is the Mercedes Benz R129 SL a future classic?

Posted by Carl Burgess on 18th Jun 2018

Is the R129 SL 500 a good investment in 2018? Is the R129 a future classic?

In short - yes. In fact, the R129 is a current classic. It was a classic the day it was born in 1989!

I'm noticing that the SL is beginning to get attention from investors, rather than just enthusiasts. Bruno Sacco's range of two door R129 SL roadsters (wiki), in production 1989-2001, are known for their fantastic build quality, timeless design and sophisticated craftsmanship.

Future outlook for the SL

The R129 is seen today as a highly desirable modern practical classic car. It commands a higher average price than its successor, the R230 SL, not least due to its mechanical simplicity. There is no time in history where the value of the R129 has declined. Doubly, the car is experiencing a surge in popularity and market value, making it a fantastic choice for investors. Our sources estimate, over the last five years, a 25-30% increase in the value of mid-spec examples. Low mileage cars have seen a 75-100% increase. 

History dictates that decent examples of this model will continue to appreciate, with the very best rising to many times their initial value. The V12 model can still fetch £30k or more at auction. Facelifted models are generally more sought after, which come with a number of higher quality fixtures, fittings and parts. 

".. the [R129] SL is handsome and has plenty of smooth power from its V6, V8 or even V12 engine. Best of all, it’s half the price of its SL R107 predecessor yet much easier to live with. Rare AMG models and special editions will increase in value more than standard cars.’" - Jeremy Clarkson

Which Mercedes Benz R129 SL models are good investments in 2018?

Here is a summary of the good and bad habits of each R129 model, from the perspective of an investor:

300 SL

GOOD
- Entry level price. 

BAD
- Agricultural performance


300 SL-24 Valve 

GOOD
- Pure classic. 

BAD
- KE-jetronic fuel system is tricky to diagnose


280 and 320 V6

GOOD
- Gutsy, pretty much bombproof engines.
- Easy to diagnose issues and parts aplenty. 

BAD
- Interior build quality lacking.
Mercedes no longer supplying coded key fobs, and matching corresponding ECU.
- The later central locking pumps are no longer available.


500 SL

GOOD
- Big grunt. 

BAD
- KE-jet tronic fuel system tricky to diagnose.


SL 500 

GOOD
- Superb M119 engine. 

BAD
- It can bite you in the wet


600 SL & SL 600 

GOOD
- Top of the range. 

BAD
- Pre ’96 running issues complex to diagnose


SL55 AMG / SL60 AMG / SL70 AMG / SL72 / SL73 

GOOD
- Rare and desirable. 

BAD
- Nobody knows their value!

So which R129 model should I buy?

The SL 500, years 1997-1999, is by far the best build quality of the R129’s. The Motronic engine is easy to diagnose, and the build is pretty bomb proof. This is the best R129 to buy in my opinion.

For a more detailed guide on which engine sizes to go for, as well as other things to look out for when buying an R129 SL, see these two great buyer's guides - one from Klipnik, and another from Octane.

If you have any questions, just leave a comment below. If you have a part or diagnosis request, just ask the R129 Co Gurus.

Thanks and good luck! Carl