drop in mpgs?
 

I drive 90 miles 2-3 days a week to class. That is roundtrip. Lately I've noticed my mpg's drop. Now, my odometer doesn't work so I am gauging this on how many days a tank will last me.

Example, monday I had half of a tank and drove to school, then to the other school, then to the gym, then home. Total mileage.. 106 miles -ish. I blew through a half tank of gas which I then filled back up to half. Around 10 gallons from reserve light on to the half mark.

my driving style is relaxed, I don't speed, accelerate like crazy, or idle for long periods of time. The drive is 80% highway 20 % not highway (not exactly city driving).

What is going on? I need to get my odometer fixed of course. Please donate to the Help TheDon foundation by clicking this link.. ha

Other than that The air filter isn't gunked up, I'm not leaking fuel, I just put in a working MAF, the check engine light is not on, my tires are properly inflated.

I don't get it?

I see from other threads that you've got problems with your odometer - unfortunately that really is a good starting point to work out how much fuel you are using...

To make your problem a bit clearer you think you are now getting 10mpg and you'd normally be getting... how much?

Perhaps its time for a tune-up? When was your last air filer/spark plug change? I'm not the most knowledgeable on the m104..

Lemme know if you need a Odometer, I may have one around. if not, I'll have one shortly

I probably need to do a tune up. I haven't done the spark plugs since I got it. Probably should do an air filter as well. Plug wires should be fine?I really dont know tune up stuff on a gasser. Ha

Another odometer would be cool. On I can slap in temporarily while I have my original one repaired or something. I've been keeping track of my mileage so I wil roll mine up

I'll check what I have as far as clusters go, I think I still have a couple 124 speedo's around and let ya know-

Don, don't assume the spark plug wires are fine. If they are the original wires they may need replacing. Recommend checking them, or have a local indie check if they're still adequate. Your 1994 E320 cabriolet should get about 20 miles per gallon.

When you replace the spark plugs apply a thin coating of Never-Seize on the threads and make sure they are gapped per the Owner's Manual specification.

When the odometer worked inwas getting 25 mpg. And 28 if I really tried.

The weather too will effect my m104.That is air intake temps are cold engine will run choked (rich).Summer mpg for me is 28 mpg,winter 20-21 mpg.