Change to bigger oil filter based on manufacturer's specs?

Question

I have an 1988 Toyota with a 4AFE engine. It uses a small oil filter. For the prior model year of cars with 4AFE engines, 1987, Toyota recommended a filter which was larger than the one they recommended for 1988. Same engine, same model car, but for some reason they changed the size recommendation of oil filter to a smaller one. Can I switch to the larger filter -- which is made by the same manufacturer? It has same filter material, but more of it, although probably it has a lower oil pressure due to its larger volume of filter, and, of course, I would need to add a bit more oil, but I never run the engine topped off with oil -- don't want to blow a gasket. I usually fill up to 95% of capacity -- my car's tolerances allow up to one quart low.

My car already has a built-in (stock) oil cooler: it's located in the driver's side rear quarter panel. Hot oil is circulated along the side, into the oil cooler, and then back to the front of the vehicle. It's a long distance for the oil to travel, but I suppose that exposes it to more surface area for it to cool down.

I currently use a Purolator filter with 96% efficiency, and the larger filter is also a Purolator but with 98% efficienty. Given your advice, I could switch to either an Amsoil or Mobil 1, both with 99% or greater efficiency. Prior to posting my question, I had been researching magnets (Filtermag, EngineSentry, homebrew varieties), but I never considered bypass filtration; I'll look into that option as well.

Answer 1

A better alternative would be to go to an additional by-pass oil filter. A by-pass oil filter filters to less than .5 microns and acts as an additional filter for keeping the oil cleaner. You would have to add additional oil for the additional filter as well.

Running your engine slightly low on oil is like running yourself in a near dehydrated condtion. NEVER run your car low on oil even though it is within the Mfgs spec. Oil not only acts as a lubricant but also as a cooling agent and a depository for dirt.
On the other hand NEVER over fill your engine. That can cause other problems such as foaming caused by the oil being whipped by the crankshaft.

By-pass oil filers extend the life of your engine by nearly double and are commonly used in heavy trucks. Adding one to an automobile engine is just extra insurance. See the link below and check out the rest of the Amsoil site for additional information.

Answer 2

Run the larger filter as long as it does not interfere with anything and is the same as the smaller one as far as having an oil bypass or check valve. The larger filter will do a better job of filtering and help cool the oil better and will not affect the pressure---that is determined by the pump. Use to be an old racing trick we used on Chevy small block engines by using a PF35 truck filter in place of a PF25 normal filter. We also use to put large bar magnets on the bottom of the filter to help trap any small metal particles from circulating in the oil and causing faster engine wear. You should keep the oil level up to the max level and you'll have to determine how much extra oil to add to compensate for the larger filter......don't let it fall below 1/2 quart low especially on smaller engines which tend to run hotter than V6 or 8.

Answer 3

I had an 88 Corolla and used a larger filter on it for years with no problems. The added length did not interfere with anything. I simply looked at filters at the store which had the same thread and o-ring diameter but were longer. Had 175K miles on it when I traded it in for a 2005 Corolla. Sorry, I don't have the owner's manual anymore or I would give you the part number.

I always felt the added filtering could only help. do it.

Answer 4

Good for you for wanting to have better filtration. Here's an article on a SAE paper on the correlation between particle size and engine wear:
http://www.amsoil.com/news/2007_july_filtration.pdf

I agree with the post about bypass filters. But, if you don't want to run one of those, why not choose a full-flow filter with the highest efficiency, Amsoil EaO: http://www.amsoil.com/redirect.cgi?zo=1463115&page=StoreFront/eao

Answer 5

they went to a smaller filter because of space requirements