Differences in oil caps?

[project 500]

In the process of riding up my car lol, am trying to get a decent looking oil cap. Some say they are fine to fit all RBs or even all Nissan, others like a stock GTR oil cap say rb20/25/26 but they won't fit a neo rb25. Is this due to the stock plastic engine cover or is there something else different?

[TurboTapin]

On 6/28/2022 at 10:16 AM, project 500 said:

In the process of riding up my car lol, am trying to get a decent looking oil cap. Some say they are fine to fit all RBs or even all Nissan, others like a stock GTR oil cap say rb20/25/26 but they won't fit a neo rb25. Is this due to the stock plastic engine cover or is there something else different?

My understanding is all Nissan oil caps are M32 x P3.5, including S1, S2 and Neo RB25's. 

What makes you think they are different? 

[hardsteppa]

Because there are differences in the caps.

Possibly other reasons too, but i belive it's the length of the threaded section.

[TurboTapin]

On 6/28/2022 at 5:49 PM, hardsteppa said:

Because there are differences in the caps.

Possibly other reasons too, but i belive it's the length of the threaded section.

As a sanity check, I verified a few popular brands like HKS, Nismo, Top Secret, Tomei, etc. and all have the same part# for S1, S2 or Neo. 

Are we sure they're not the same? Because I'm pretty sure they're the same... 

[TurboTapin]

Since I really take this oil cap science seriously I decided to take this even further...

I confirmed with Nissan EPC that both older and newer style nissan oil caps (15255-1P103 & 15255-1P110) fit all RB25's. I then realized I have three Nissan's with both of these caps in the driveway so I did what any grown man would do... I ran out and interchanged them. They all fit. 

Btw while on the topic, the newer caps (1P110) that I have on my Sentra and Rogue are garbage and can never be undone by hand. 

Cheers. 

Edited June 28, 2022 by TurboTapin

[project 500]

Cheers lol,  I think the Jun oil filter caps say they only fit rb20 and rb26.

Also saw on another site that a stock GTR cap didn't fit a neo. I only have a Neo r34 so can't really check for differences

[TurboTapin]

On 6/28/2022 at 9:27 PM, project 500 said:

Cheers lol,  I think the Jun oil filter caps say they only fit rb20 and rb26.

Also saw on another site that a stock GTR cap didn't fit a neo. I only have a Neo r34 so can't really check for differences

Keep this up and I'll end up doing my doctoral dissertation on oil caps... "Oil cap variations and its adaptive consequences on society" 

[project 500]

I look forward to it lolol

[hardsteppa]

 

On 29/06/2022 at 8:19 AM, TurboTapin said:

Since I really take this oil cap science seriously

jeezuz lol, seems you do! 

this is what i was referring to though>

https://www.ebay.com.au/itm/192826325873?hash=item2ce5583b71:g:1vEAAOSwWflims5D&frcectupt=true

Now - from my measuring on Rb25det's, it seems there's thread room, so either cap would fit, but I didn't say 'won't fit", I said that there are differences. 

[project 500]

https://www.jdmgarage.com.au/shop/engine/engine-accessories/oil-caps/genuine-r32-gtr-oil-cap-15255-d5501/

That says non neo rb25, I just though maybe it didn't clear the plastic cover or something