I, like all of us hypermilers out there get that gut-wrenching feeling every time my vehicle drops 1/10 of a mile. Conversely, absolutely elated whenever it goes up. I can only drive so slow, pulse and glide so much, and obviously reduce my driving needs (read: ride my bike). But there is something in the way of the guts of the system. I have switched to a pennzoil full synthetic for quite some time now, and I have maintained a consistent 28.6 mpg through all seasons. This is an increase from my 25.6 that is in direct correlation with when I changed to a full synthetic.

This last oil change, I stopped using Fram Tough Guard filters and started using Wix filters. I now get a great 28.9 mpg. What does that mean? Over a single tank, that's 4.5 miles. Over a 5,000 mile oil change interval, it is an increase of 60+ miles. Just from my filter performance, I think I'm going Wix.

I decided that I am going to be using Wix oil filters, cabin air filter and air filter. More importantly, changing to a Wix air filter means I can now FIND the filter. I have been having a heck of a time trying to find the air filter on shelves without going to the dealer, but there is an alternative. Have others noticed the same increases?

We also changed our to a wix filter as well and have just now run about a full tank out. I thought that it was solely the colder temps (and thus less A/C use) but now that you mention it, it might also be the wix filter. I got mine online from rockauto for $10.49 plus shipping but it and the cabing filter and shipping was $29.90. However, we got the ATP cabin filter (as it has charcoal which helps filter the cabin air better). It might have added 1/2 mile per gallon?

ATP cabin air filter? Where may I find that?

The oil pump can easily consume a few HP at higher rpms so a lower restriction oil filter can marginally contribute to better mpg.

I am using an over sized Mobil 1 M1-209 oil filter. It's the same diameter as the standard OEM filter but at least one inch longer for many more square inches of filter media and thus lower back pressure and pumping restriction.

All the filter sizes are typically the same price from a manufacturer so the extra capacity comes free. The drain back valve, bypass valve, and gasket size are all the same specs as the OEM filter.