RP 20-820, 10K Miles

[Jim Allen]

Here's the autopsied Royal Purple 20-820 that was on my '05 F150 for a bit over 10,000 miles and close to two years (19 months). Nothing noteworthy to report. Looks in good shape. Noted some drippy glue where the media was glued to the endcap, something that happened during manufacturing. Was used with RP 5W20, UOA pending.

 

[Texan4Life]

Great pics of a great filter!

 

[OVERKILL]

Looks very similar to the Fleetguard stratapore for this app. Only difference I can readily pinpoint is that that Stratapore uses a coil spring vs the leaf for the RP.

 

[Jakegday]

looks great! i say weld her back together and run her another 10,000

 

[tig1]

Is the RP made at Champion Labs in Illinois? Looks similar to a M1.

 

[Jim Allen]

Yeah, it's made by Champ. Might have a different media. I don't have the M1 Betas handy.

 

[ltslimjim]

^Yes, different media. IMO, RP/M1/K&N all have their strengths. K&N is probably best for racing, M1 is a middle ground, and RP probably has slightly higher efficiency rating.

 

[JOD]

Originally Posted By: ltslimjim
^Yes, different media. IMO, RP/M1/K&N all have their strengths. K&N is probably best for racing, M1 is a middle ground, and RP probably has slightly higher efficiency rating.


I think the only thing that makes the K&N 'better for racing' is that it says 'K&N' on it...

I posted a flow chart for the RP 20-820 a while back (unfortunately I don't have it on this computer, and I can't find the link on here). The filter seems to flow better than just about anything out there, with the possible exception of the Ford Racing filter (the test parameters were different, so it wasn't a straight-up comparison).

The RP filter really seems like a more robust design than either the M1 or the K&N (which I *think* are identical filters); the full synthetic glass media with metal screen backing is definitely different that the synthetic blend media used in the other filters.

So Jim, putting the filter back together from your pictures, I'm assuming the bypass is in the base?

 

[ZeeOSix]

Originally Posted By: JOD

So Jim, putting the filter back together from your pictures, I'm assuming the bypass is in the base?


You can clearly see in the 2nd photo that the bypass valve is in the end cap that is on the dome end of the filter.

 

[ltslimjim]

Originally Posted By: JOD
Originally Posted By: ltslimjim
^Yes, different media. IMO, RP/M1/K&N all have their strengths. K&N is probably best for racing, M1 is a middle ground, and RP probably has slightly higher efficiency rating.


I think the only thing that makes the K&N 'better for racing' is that it says 'K&N' on it...

I posted a flow chart for the RP 20-820 a while back (unfortunately I don't have it on this computer, and I can't find the link on here). The filter seems to flow better than just about anything out there, with the possible exception of the Ford Racing filter (the test parameters were different, so it wasn't a straight-up comparison).

The RP filter really seems like a more robust design than either the M1 or the K&N (which I *think* are identical filters); the full synthetic glass media with metal screen backing is definitely different that the synthetic blend media used in the other filters.

So Jim, putting the filter back together from your pictures, I'm assuming the bypass is in the base?


You're probably right regarding K&N, to an extent with the brand sell, but I'd imagine some apps it allows for best 'flow', of course then there is the pressure argument as well. Again, an attempt to generalize fails. Ugh!

They are different compared to an M1, though.

 

[ZeeOSix]

Flow restriction of an oil filter only comes into play when the oil pump is operating at it's max pressure setting. A more restrictive filter will also make the oil pump hit the max pressure point sooner.

But if a more restrictive filter never makes the oil pump hit maximum pressure setting, then the flow will not be degraded.

 

[JOD]

Originally Posted By: ZeeOSix
Originally Posted By: JOD

So Jim, putting the filter back together from your pictures, I'm assuming the bypass is in the base?


You can clearly see in the 2nd photo that the bypass valve is in the end cap that is on the dome end of the filter.


Well, it kinda looks like it to me-but with the pic I can't tell if that's just used oil causing a reflection. If someone from RP hadn't told me that the bypass was in the base, that's what I would have thought, too! That's why I wanted to check with Jim.

 

[Sayjac]

Agree with ZO6, this app sure looks like dome end to me, with the darkened recessed dome end center circle (bypass). But, the RP display ads seems to show dome end. But, not all M1's have thread end bypass either.

Nice filter, just a bit pricey for my average OCI's.

 

[glum]

Originally Posted By: sayjac
Nice filter, just a bit pricey for my average OCI's.

So use it for 2 or 3 OCIs.

 

[ltslimjim]

^I wouldn't mind using a RP filter for up to 15,000 miles/1 year unless I knew or even suspected that my engine was dirty or in some sort of cleaning phase.

 

[HTSS_TR]

I already using low/medium premium oil filters, Bosch Premium or Motorcraft ..., for 12mo/13-14k miles in my '94 LS400 for more than 15 years.

 

[DragRace]

Thanks for posting pictures!

Gonna run a RP oil filter here soon myself,with some Amsoil ASL I need to use up.

 

[Jim Allen]

Dome end, definitely. I would prefer a base end but I'm not fixated on it. If we could get the MC 820s design with a bit better beta, I'd be in heaven.

I am STILL waiting for my used oil analysis (new lab I have tried) and that will tell me a bit more on how this filter worked. I discovered a long term air filter issue not long before I did the oil change that might lead to very high silicon. I'm hoping the RP filter helped me out a little in this regard.

I have a P1 on their now (K-Mart store close out) but if I could easily buy RPs at a discount chain for a semi-reasonable price, I would.

Ultimately, since I am soon going to an added bypass system, I may revert back to MC 820s

 

[ltslimjim]

Originally Posted By: Jim Allen
Dome end, definitely. I would prefer a base end but I'm not fixated on it. If we could get the MC 820s design with a bit better beta, I'd be in heaven.

I am STILL waiting for my used oil analysis (new lab I have tried) and that will tell me a bit more on how this filter worked. I discovered a long term air filter issue not long before I did the oil change that might lead to very high silicon. I'm hoping the RP filter helped me out a little in this regard.

I have a P1 on their now (K-Mart store close out) but if I could easily buy RPs at a discount chain for a semi-reasonable price, I would.

Ultimately, since I am soon going to an added bypass system, I may revert back to MC 820s



Actually, that's a great reason to run a filter like RP offers for even a cleanup phase. That is if it indeed can catch the dirt before wear rates get going at a faster rate. Bypass implementation probably will cause a RP to be over-overkill.

 

[Sayjac]

Originally Posted By: glum
Originally Posted By: sayjac
Nice filter, just a bit pricey for my average OCI's.

So use it for 2 or 3 OCIs.
Well, I could but I wouldn't run it more than two OCI's tops in any case.

Thing is, when I can buy 3-4 (with rebates now) new P1's for the cost of 1 RP, I'd prefer to put a new P1 filter on. Just not seeing any cost benefit of reusing the RP. That said, I am considering a Bosch DP I got for ~$4.50 for two full MM OCI's on my Honda.

Originally Posted By: Jim Allen
If we could get the MC 820s design with a bit better beta, I'd be in heaven.
And there in lies the rub with using MC filters. The stated 80%@20um will always leave some question mark regarding the true efficiency of the quality made filter.

As for the thread end dome end discussion, it seems that some prefer thread end for the bypass/silt wash reason, which is fine. For me though, thread or dome end, isn't that big a deal either way. Even all MC filters aren't thread end.