Mileage per gallon

Hi guys! I have another question!
Which engine provides better mileage per gallon? The 3800 Serie I or the 3800 Serie II with 205 horsepower? Could it be possible that the more powerful one is more fuel efficent than the older one with less horespower?

What fuel quality is requiered for the 3800 ccm engine without supercharger? If have heard that petrol with only 87 octans is used for this engine type in the US! Could this be possible? German cars for example need at least 95 octans!

Thanks Lucas.

I average about 14mpg with a series I, but I thouroughly enjoy my car :)

Run 87 in either naturally aspirated engine, Run 93 in the SC variants

In general, the newer engine is more fuel efficient.

My 92 with SC is getting almost 28 mpg (about half city and half highway). I have been using 87 octaine with no problems. The engine computer compensates for the lower fuel quality.

the computer will compensate, however, you'll get better performance from 93, its a tradeoff of sorts.

My car also idles alot, and does almost entirely city driving, so crappy fuel economy is expected.

My 95 Park Ave (not Ultra) gets 30 mpg using 87 octane on a 240 mile trip with the cruise control set on 70. Around town it only gets 18. The car is stock with 215/60SR16 Yokohomas and only 20,000 miles. I am using Mobil 1. I would love to get a little more power out of the engine but I'm afraid to mess up the gas mileage.

Has anyone tried a K&N air filter kit?
Was there any noticable increase in power or economy?

My cousin tried a K&N square filter on his old 91 park ave. Didnt do a darn for it. I've read that the cone filter and a new duct system works well.