the 123\TUNE-4-R-V-M is designed for the W110, W115 and W123 engines, in the Mercedes :
For cars with Bosch ‘D-jetronic’ injection-systems, order the non programmable 123\MERCEDES-4-R-V-IE.
If you want to tune your engine, or you have an engine for which there is no standard distributor available….. And you are a Windows PC user, the 123\TUNE is the answer! By connecting it to a computer, you can easily adapt the 123\TUNE to fulfill even the most demanding requirements. The unit offers two sets of curves that can be selected by placing 12 Volt on a wire from the 123\TUNE. Handy, if you’re driving on two different fuels, like regular fuel with LPG or with Ethanol