Regular or plus unleaded in a 190e 2.3-16?
 

Anyone using regular or plus instead of super in their 16 valve 190? I know the car says too use premium/super unleaded. The resistor is still in place that back the timing back. R16 i think its called.

I would stay with the 91 octane , as recommend. The difference in price per gallon is minimal, relative to the decreased "mpg", you will see with 89 octane fuel.

The cost of premium, vs regular, is actually minimal right now, considering the the efficiently of the proper fuel.

Given the compression ratio and powerband in the twincam, using a lesser fuel in the 2.3-16 is false economy. The M102 engines don't have knock sensors and the valves on Cosworth head are pretty sensitive as it is.

Really, break out a calculator and figure out what the cost difference is on that 70L tank.