I called him up to find out he gets 24-28mpg in his 560sel.

Ad reads:
Mercedes Benz 1985
loaded,AC,sunroof,
nice. EXC. MPG $2800.
obo. 417-887-5233

I thought it might be a diesel with the 'EXC MPG' in the ad..... Nope, a 560sel.

I told him "I never heard of such a claim; these cars had a gas guzzler tax imposed on them. They get deplorable gas milage".

He still claimed excellent gas milage.
You people are completely free to call him up and set him straight.