View Single Post
Old 07-16-2008, 05:04 PM   #13 (permalink)
EcoModding Lurker
Join Date: Jul 2008
Location: Richmond, VA
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
I own a small industrial filter company, and I just switched all the oil filters in my small fleet of company cars over to a longer oil filter. I drive a Toyota Echo and didn't have to make any modifications to the car to make the change. Since I work in the filtration industry, I thought I'd share my reasons for doing so, as well as some of the technical aspects of switching to a longer oil filter for any that are interested.

First off, I recommend checking the specs of your new filter with the filter manufacturer's tech department before making the change, as you can damage your car if you accidentally put a filter on there with a higher bypass setting or micron rating than what the OEM recommends. Also, it's possible you will void your car's warranty by using a filter that's not recommended by the factory. I suggest sticking with a high quality filter OEM such as Baldwin, Mann, or Donaldson. I'd probably avoid Napa or Wix.

My second recommendation is to fill your longer oil filter half-way up with oil before installing it. If you can't do this, you may want to stick with the original filter. Otherwise, you car will run "dry" on startup (very little oil in it) a little longer than usual. This could damage your engine.

I changed from a Baldwin B33 oil filter to a Baldwin B7238. I double-checked with the factory and compared the surface area of the two filters (this is probably the most important spec), as well as making sure that the internal bypass valve and micron rating were the same between the two filters. Basically, the two filters were the same, except one filter had 88.6 square inches (B33) of media, and the other had 163.8 square inches (B7238).

The reason that surface plays such a big role is because it lowers the pressure drop across the filter. And yes, this pressure drop can be substantial (I think up to 20 psi when dirty - same as the bypass valve setting). Not only does this reduce the amount of work needed to pump oil through the filter, it also allows the filter to remove particulate more efficiently and operate effectively for a longer period of time. In fact, the biggest reason I changed to an longer oil filter wasn't to improve MPG, but to improve vehicle performance during extended oil-drain intervals. In other words, if someone went 2500 miles past the usual oil-change point, the filter would still perform well.

However, I have noticed a very, very slight increase in fuel efficiency, although I have not measured the difference scientifically. I've purchased a ScanGauge II from amazon and plan to try and test the difference the next time I change oil. I doubt if it's a huge difference at first, but might become more noticeable the closer the car is to an oil change.

In the long term, it will definitely improve the cleanliness of your engine and keep your car running longer. That in itself is probably justification for the mod.

Also, this can be a relatively inexpensive mod. In my case, the longer filter only took the investment in time to make sure everything was kosher, plus an extra buck or two for each filter.

Hope this is helpful.
  Reply With Quote