Although Mercedes has dreams of big U.S. sales for its V8-powered AMG SL variations, the company is unsure of whether or not to proceed with exporting the ragtop AMG SL43, the new 4-cylinder version of the roadster, to the U.S.

The question of sales potential in America, where assumptions are made regarding the relevance of ecological concerns to the buyer with $150K to drop on a weekend thrill machine, is entirely valid. The SL55 and SL63 — offering 469 and 577 horsepower to drivers, respectively, by way of a 4.0L V8 biturbo — might make the SL43 redundant, or invisible.

Which would make it an overlooked gem, because the SL43 is a very interesting piece of four-wheeled hardware. Its 2.0L inline four can pump out about 370 HP, and its design features a 48-volt electric turbocharger courtesy of F1 racecar technology; the unit gives the turbo virtually lag-free performance, and also improves the car’s efficiency. In its press release, the automaker declares its use a first for a regular production model. The SL43’s RSG, or starter generator, gives the roadster a quick boost as needed.

Other componentry and performance features at work in the SL43: AMG’s 9-speed automatic gearbox and AMG RIDE CONTROL variable suspension.

Mercedes has confirmed the appearance of the SL55 and SL63 on U.S. shores in the next few months. Whether or not the SL43 will arrive with it is a matter of conjecture at this point.