I just purchased a 1993 240, with just over 100,000 miles. My question is should I run premium unleaded gas or can I run regular unleaded. Also, what kind of oil do you think is best? I know a lot of people like synthetic. Thanks for the advice.

Scott,

Use the lowest grade octane you can without pinging. I have an 86 with 214,700mi. and use regualar gas (no probleams) It doesn't seem to run any better on mid-grade or super so why pay the extra cash unless you have too. Maybe you could do a couple tankfulls each grade and do some mileage

tests to make a more scientific determination.

As for the oil everbody has their own opinions. I use Exxon Superflo...I always buy it on sale and always send in for the rebate so it usually costs me about 75 cents/qt.

I do change may oil every 2,500 miles. Most everone on this board will suggest the use of Mann filters. I am currently making the switch even though I have never had a problem with Fram. My car runs mint and does not burn any oil...in fact it's the only car I've ever had that gives back all the oil I put it (less whats in the filter)

Good luck with your new purchase...May it serve you well for many hundreds of thousands of miles !!!

Jack W.

As neighbor Phil says, try different grades of gas. My 90 ran far better on 93 octane than on anything else, and I had no driveability problems in over 200K miles. As to the oil, I switched to Amsoil at 180+K miles, and had no leaks. I did do an engine flush when I switched. Before that, I ran Castrol GTX 10w-30. I used Castrol exclusively for thirty years, and switched only because I had all the empty cardboard boxes I'll ever need. Or something.

Scott, Welcome to the board, start with reg. unleaded , if it pings upgrade to medium, if it still pings use super. In my '85 I need super, in my '87 I can use regular.I use castrol 10w30. Putting synthetic after dino oil can cause leaks.

Good luck, Phil Stone