Hey, Denis!
I don't know if the Mercs have the same issues or not, but a lot of American cars have issues with converting to alcohol. There are some gaskets/seals/rubber-type bits in the fuel system that do not like alcohol, and I have heard horror stories about the results. I'll keep my fingers crossed!
Anyway, my Dad had his own auto repair shop when I was a kid, and I hung around and helped when I could. Learned a lot there. After high school I went to college - Aviation Technology - for two years, but discovered that job pressures took away the fun. Also that planes falling out of the sky often landed on the mechanic...
Came back home and was a 'maintenance engineer' at the school system I had graduated from. Learned about plumbing and house wiring the hard way. Wanted more money, so went to work at the GM dealership. Got my ASE Master's certification, but after 8 years the job pressures led me to get the job for the Postal Service as a rural carrier. Made good money there since I could do virtually all the repairs on my car myself. Sure enough, was disabled in an accident at the lumberyard I was working at to fill in until I got my own route - and I was next in line.
Sooooo... am going back to college - again - and am a Senior working for a Bachelor in Business Administration. Hoping to go back into automotive, but this time with something more green and eco-friendly. I'd love to mess with one of Trebuchet's human-powered bikes, only battery powered since my feet are messed up. I'd be grinning like that 13-year-old that used to fix lawn mowers for his Dad so many years ago...