Oldsmobile/Buick Repair: car shaking, sophisticated computer system, delta 88

Question
I own a 1987 Olds Delta 88 with very few miles on it. The alternator was replaced about a month ago..that is the most recent repair on it.
About 2-3 weeks ago I put gasoline  in it from a local convenience store. I also filled up a gas can for my lawn mower and put that in the same day. Since then, my car has been "shaking" as it is running...typically while on the road,but sometimes just when it's at a stand still as well. It runs fine otherwise, it just "shakes" really bad. Any idea what could be causing this?
I might add..the lawn mower which recieved the same gasoline was acting the exact same way ("Shaking")...my boyfriend & I thought it must be the gasoline for it to be coincidently happening to both the car & the mower...altho, since then I have gone without putting gas in the car until the level shows well below the "E" on the dash guage..so we figured that the bad gas should be well drained out by now. What do you think?


Answer
hi mis. well i am assuming you need an answer and not the lawnmower lol.but yes you are most likely right you must have gotten some bad fuel.and yes you probably have used up all the bad gas and if not should be diluted bye now.but unlike the lawn mower your car runs on a very sophisticated computer system.so when it  ssenses a change in the way the fuel actually burns,it will try and make changes to make the fuel burn cleaner.but unfortuneately during the time it makes these changes.it increases the fire goingn to the plugs and this makes the spark plug burn hotter which makes the plug wires also take more heat.which is where your prob is .you need a tune up wires and plugs and fuel filter.your car shakes because fouled plugs and bad wires.and as would the lawn mower also.good luck mis.and please take time to rate my help it is very important to me .ty billymac