euro car need help

[maximus]

I was found out from fast lane that my car is a euro car that it wasnt built for the US was going to buy a catalytic converter from them it turns out it would not fit my car i have a 1 inlet 2 outlet converter but the one thy show in 2 in 2 out then he ask me a few question about my vin # then he told me my car was not made for the us now what do i do i know in Europe they grade they fuel differently now should i still use premium on the car or go with a lower grade any of you guys have a Euro car?tell me what u had to do please any info would be helpful

[mbtjc]

OK, your post was a bit unclear so I will do the best I can. With the cat...if you need to replace it you might as well replace it with a high flow unit and free up the exhaust a little bit. Stock cats can be a bit restrictive. I would give Random Technology a try (www.randomtechnology.com). You can get a universal cat in any diameter and any number of ins and outs you want. With the gas...what does it say in the owner's manual? Try 91 and see if it knocks. If it does, then go to 92 or 93. If you can't find anywhere what it needs, then you may just have to experiment a little, but generally speaking, Mercedes run on Premium.

[JimSmith]

maximus,

If your car had a factory installed Euro emissions system, you will have a small black, 1.5" or so diameter, plastic knob on the driver's side front fender with green lettering on it. It is an ignition timing selector and you set it according to the octane of the fuel you buy. If the car came from Germany with the factory installed system you will have a little decal under filler flap, and possibly one in the glove box, that says "Super Bleifrei" which is lead free high test. Which is 91 octane to us. If you use a higher octane you can set the knob to the "no resistor" position and get a few more hp. To find that you have to take the knob all the way off and look under the cap for how the pins are arranged. On the outside you will see "N" and "S" for "Regular (Normal auf Deutsch)" and "Premium (Super auf Deutsch)" and a bunch of other tick marks for in between octane ratings, as well as one spot with nothing. The nothing position, I believe is the no resistor position, but check it out yourself - the scheme is visible when you look inside.

If you have a Euro car that was modified over here to put an emissions system on it the car needs 91 octane or better. The octane rating is based on the compression ratio and almost all Euro models had 10:1 or so compression ratios. To run on a low octane and not knock cars use compression ratios around 8:1 or so.

Enjoy the car and good luck, Jim