hello, first time user on here. I have a 1985 Mercedes 190e which I bought about 9 months ago. It has recently started to use a lot more gas, an unbelievable amount. I am going to the gas station every day and it's getting expensive. I am guessing it needs a tune up but I am not a mechanic so I don't know what it could be. I just know it didn't do this before and any advice would be appreciated.