A mid-cycle facelift was introduced in 2016 for the 2017 model year. Launched early 2016 in California, the revised SL400 (renamed SL450 in the US) featured a 3-litre 362 hp (367 PS) Biturbo V6 mated, for the first time in the SL, to Mercedes' 9G-Tronic PLUS 9-speed automatic transmission.
Cosmetically, every SL received a revised front end, front grille treatment and larger non-functional side 'vents' behind the front wheels. All variants also received adaptive LED front headlights with integrated daytime running lights and turn signals, leaving the below-bumper intake area free from lighting. The LED taillights received single-colour red or red-and-amber lenses instead of the red and white of the pre-facelift models.
Front and rear bumpers were redesigned to appear more like Mercedes' other recent models, while convenience and driver assistance features introduced earlier on other Mercedes models were made optionally available. These included revised Active Body Control (ABC), now with the "Curve Tilting" function from the S-Class Coupe. Externally, the SL63 and SL65 were distinguishable from the non-AMG variants by embellishments to their bumpers and side sills in gloss black or polished aluminium, respectively. The SL63 and SL65 also featured trademark AMG 'twin lamella' front grilles and dual twin tailpipe exhaust trims as well as a carbon fibre composite trunk lid.
A slight revision to the folding 'Vario-roof' hardtop meant it could deploy at up to 40 km/h (25mph) without the luggage compartment partition having to be deployed in a separate manual operation.
Interiors continued virtually unchanged in 2017 with the exception of slightly revised minor switchgear and a redesigned steering wheel.