Dealer says that Prius has a "wet" oil filter

Sounds like BS to me. You can use any brand of filter you want. I have a Fram in mine right now. Next time I think I'm going to try a Purolator.

 

It's definately a "wet" filter because the oil runs down my arm when I unscrew it. I think it's nice to have the filter mounted like it is though, with the open part up, because I can fill the new filter with oil before I put it on.

 

Fram is a widely-known brand name, but the accounts I've read it doesn't appear to be a 'quality' filter. The Toyota filer doesn't appear to be special except for their filtering methods, but does seem to be of high-quality. For a few bucks every 5,000 miles, why not? Especially if you put a lot of importance in oil changes, as I believe you do. As for wet, I don't think the filter is special because of that.

Here are some related threads that may give you more info:

http://priuschat.com/index.php?showtopic=11100&hl=
http://priuschat.com/index.php?showtopic=8323&hl=

 

I guess I could have said a little more about the "wet filter". I think what that really means is that the filter has a check valve in it to prevent the oil from draining out when the engine is stopped. Apparently back in the "old days" some filters did not have such a valve and on engines where they were mounted with the open part down the oil would drain out when the engine was stopped. So the filter had to be filled by the oil pump each time the engine restarted, instead of just once when you first replace it. The oil would not get to the engine until the filter filled up which caused a lot of wear on engines that were stopped and started often.

This is, of course, not a problem on our Prius. For two reasons: 1. the filter is mounted with the open part up so it stays full and 2. as far as I know all modern filters have a check valve in them anyway.

I have been using Toyota oil filters, the dealer here sells them for $5.00. I think that's about the same as the premium Fram Tough Guard or the premium WIX.

Do a search for B mode there is a lot of really good information at this site about that featue. As others said what you were told is totally wrong.

 

As others have stated, the filter does have a check valve, but it doesn't actually do anything because the filter is mounted from the bottom of the engine and unless Toyota also adds an additve to their filters that changes the laws of physics, oil does not flow uphill, so the check valve doesn't do anything..

The other half of the equation is the oil pump- the trocoid pump delivers pretty much instantaneous oil pressure as soon as the shaft is turned..

As far a filters go, I normally use a genuine Toyota; I've never been convinced that Purolator or Wix are any better... The last oil change I did, I couldn't make it out to the dealer, so while I was a the Canadian Tire getting the Amsoil 0w30, I picked up a Fram Extended Guard (also called the X-1 in the US I believe)- this is their top-of-the-line filter: synthetic media, steel end caps, silicone valve, etc.. Unlike the cheap standard Fram filter, reviewers who have cut this one open have compared it favorably to other high-end filters...

 

There are two main safety components built into almost every screw-on oil filter out on the market. The first one you see when looking at the mounting surface of the filter is the anti-reversion gasket. It is just behind the various holes which surround the threaded hole in the filter body. This is the thing you referred to as the check valve. Its main purpose is to keep all the containments within the filter once the inbound flow and pressure has ceased.

The other valve in the filter is a pressure relief valve located inside the body at the top. Please look at this following link to get a better idea how filters are built.

Since I was not there to experience the communication between you and the mechanic, this is just a big s.w.a.g.

 

Toyota does have a special filter with a check valve. It's used on all their cars. You can get a 10 pack for about $40 online, so you can use a genuine filter and have the oil changed anywhere you like.

Nate

 

10 filters for $40 is a very competitive price for factory branded filters, especially when Purolator PureOne filters (their best and a very good filter to boot) are priced comprably at PebBoys or Bi-Mart (for those of us living in Washington/Oregon).

 

I'm waiting for my father to suggest I install a Frantz Oil Filter like he did in his 1964 Plymouth Fury.

 

Your pops had good intentions. Studies have borne out that if you can filter down to 5-10 micron absolute, engine wear will be insignificant. More than likely, due to the pressure drop, it has to be done with a bypass filter in combination with the regular full-flow filter (25-60 micron absolute).

I've seen very large V-12 and V-16 Waukesha motors at refineries and terminal gas piping stations. The filter manifolds are very impressive. They even use centrifugal canisters - the centrifuge is driven by plant air - to get the soot and heavy particles out.

The oil is only changed when used oil analysis indicates.

 

The "wet filter statement" Is because the filter is mounted on the engine so that the filter is always full of oil. If it was mounted sideways like some are then oil would drain back to the oil pan and upon startup the filter would have to be refilled. This is probably undesirable for a hybrid with all the stopping and starting.

 

"Micron" is a software - hardware company in Silicon Valley, California. In the US measuring system, SI, I think you are referring to a "micrometer" (one-one millionth of a meter), abbreviated as µm.

 

micron-software is indeed a software company

micron |?m??krän| noun a unit of length equal to one millionth of a meter, used in many technological and scientific fields. ORIGIN late 19th cent.: from Greek mikron, neuter of mikros ‘small.’

You are both right :lol:

 

The Greek "mikros" or Micron is one millionth of a metre. I would have preferred the mu, but I didn't know how to make this stupid editor produce the mu. I know there is an ISO for it but I sure don't feel like looking it up

 

Correct on all counts, my conversion factor book says a micron = 1 x 10 to the neg 6. (of a meter)