Would running a thicker oil benefit a car with an Intake?

[sdude2k2000]

I have a 2005 Mazda3 2.3L with an aftermarket cold-air intake. I've already had several OCI runs on the car (with only 19,000mi on it thus far). Those OCI's have included Motocraft 5w20, Mobil 1 EP 5w30, GC 0w30, and currently Havoline 5w20. My gas mileage seems to be a bit better and more consistent when running a thinner oil (to be expected), however would the stronger & thicker films of the 30 weights benefit me in the long run over the 20 weights?

As of right now... I really don't know what to do. Here's what I'm thinking:

A. If I run a 20 weight, I think I'll probably give the Amsoil XL 5w20 a run for its money... because every UOA I've seen done with it (especially the couple on the Focus Zetecs) seem to show it to be a very formitable oil. Or should I just stay with the Havoline 5w20?

B. If I go to the 30 weights, I have a stash of Gold GC in my garage that I could use, or I can hit up Wal-Mart and get a 5-quart jug of the M1 EP 5w30 and run that.

As for my driving style... I do a lot of around town stop & go driving (now), but I still give the car a good 60mi round-trip run at least once a week. I do enjoy a pretty "spirited" run through the Southern Oregon hills from time-to-time, so my RPM's may climb here & there

.

Any input would be appreciated guys, I am an avid car enthusiast, and I just want the best for my car. And please... save the "take off that intake!!!" line, because I love my intake and the performance that it's given me

.

 

[KJA426]

The intake should have no bearing on your viscosity choice. Most of the 5w-20 oils seem to hold up pretty well but a 10w30 would probably work okay too.

 

[JohnnyO]

I don't see that the weight of oil would make any difference because of the CAI. The silicon would likely be higher on a UOA from the intake, but it looks like you change it enough that it shouldn't be a problem.

 

[Eli89SHO]

Umm, An engine without an "intake" wouldnt run properly. Every engine has an intake of some sort. Stock or aftermarket, an intake is an intake. I dont think the oil weight should should be selected differently from what the cars manual recommends. What weight oil is recommended for your engine?

 

[Mitch Alsup]

A cold air intake might change the power of the engine by 5% if you are very lucky (2% is more likely). This is not enough to change the interior loading in the engine by even as much as the power gain.

So, if a xW-20 oil was good enough before, it is highly unlikely that it has suddenly become insufficient.

 

[sdude2k2000]

My intake (Injen) uses an oiled cotton-gauze filter, and is NOT enclosed in an airbox of any sorts. I guess my train of thought was not in the aspect of some kind of "maniacal power increase"... so much as it was to provide a thicker film barrier in the event of poorer filtration.

Forgive my ignorance on the matter... if I'm way off, please let me know.

 

[Pablo]

Better to filter the dirt out than try to select a thicker oil to "make up" for chunks that make it through an inferior air filter.

 

[Curious Kid]

I second your recommendation Pablo. So much so I went back to a stock filter. I rest easy knowing people have gone 200, 250k or more using just that - stock.

Could another type have done better? Don't know personally, but I'm willing to listen to the figures at the end of someone else's engine life.

If any mpg gains come from allowing greater intake air flow via less restriction, and thus resulting in lower shifting rpms, then one might alter the thottle plate shape and give it a knife edge, so as to allow more airflow at smaller throttle advance. On the downside with this approach is that the throttle becomes increasingly touchy, due to a greater appearent opening per throttle input. WOT gains if any come only from having knife-edged the throttle plate, so filter restriction still applies.

I guess one could say it's a compromise between total output vs. engine longevity that one is playing with here as relavent to the intake system, because any debries that enter the cylinders, has an opportunity to get caught-up in the rings, wearing them, the piston groves and cylinder walls before getting mixed back in the cylinder charge or going into the crankcase oil. In the oil and upon recirculation, these debries might be able to get past (via filter bypass) or through the filter and again work as an abraiding medium or worse, becoming lodged within bearing clearences.

You can still run a stock configuration, with the exception of removing the warm air intake from the exhaust stove, and setting the cold intake gate to remain open - on my vehicle it's thermostatically controlled by a wax cylinder unit much like that used to control coolant temperatures. You could go even further by removing that gate assembly and setting up your cold air intake duct in it's place. Just mind the intake duct enterence so as it doesn't ingest water splash and stones.

I'm not trying to sound paranoid, but I'm just trying to protect my daily driver...from myself I suppose.

I guess you can see where my priorities are at.

Happy Holidays

 

[moving2]

Eli89- Ummm....he didn't say his car did not have an intake before he modded it with an aftermarket cold-air intake. I thought it was implied that "car with an intake" in the subject heading referred to the aftermarket cold-air intake he described in his post.

 

[the_oil_dealer]

I'd run a 5w30 minimum. Should any silicon/insolubles get in there, it'll do less damage. You know when a car is just started, oil does/will go through the filters bypass valve... including impurities. I mean a CAI also suggests youre driving a little more assertively than your average grandma, who is just fine with 5w20

 

[sdude2k2000]

^--- that's exactly my train-of-thought. Anybody else have any input?

 

[moribundman]

quote:

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My intake (Injen) uses an oiled cotton-gauze filter, and is NOT enclosed in an airbox of any sorts.

---

Alright, why do you call it a "cold air" intake? I assume your cone filter is sweating under the hood. exposed to under-hood temps.

Not using an airbox may not be of advantage in terms of torque either. If you've shortened the intake path you have also likely sacrificed low-end torque.

 

[drive4show]

With the cone filter in the engine area, that's usually called a short ram intake (SRI).

For my car, a cold air intake (CAI) puts the cone filter in the wheel wheel just in front/inside the right front wheel.

That leads to SRI vs. CAI debates. Shorter tube with warmer inlet air, versus longer tube with colder inlet air. Different effects on horsepower and torque dyno readings. Chance of hydrolocking. Name brand ("paying for quality") vs. ebay ("it's just a tube and filter").

I think this is the first time I've seen a tie-in between CAI/SRI and BITOG "what oil should I use".....

 

[sdude2k2000]

^--- exactly why I started it.

 

[Darryl]

sdude:

I have a 2006 Mazda3 5-Door. I run Torco SR1 5w-20 and that's what I'd run if I were you.

The SR1 5w-20 has an HTHS of 2.9, and a 7.31 viscosity @100*C.

That HTHS of 2.9 is as high as some 5w30 oils, both synthetic and dino!

I'm going to install the Mazdaspeed intake and cat-back pretty soon, and Torco SR1 5w-20 will still be the oil that I run.

By the way, I live in the SoCal high desert and we see temps above 100*f for the whole summer! And I have no second thoughts of running the Torco 5w-20.


Darryl

 

[sdude2k2000]

Wow... great input Darryl, thank you! I think the oil I'm considering the highest would be the Amsoil XL 5w20, but I will definitely look into the Torco SR1 as well.

 

[sdude2k2000]

Darryl: Where do you purchase the Torco from? The mfr website is pretty pricey...

 

[moribundman]

quote:

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With the cone filter in the engine area, that's usually called a short ram intake (SRI).

---

How can there be ANY ram effect if you have the filter simply sitting in the engine compartment? The engine will simply suck as much air in as it can with available vacuum (or rather low pressure). You'd have to have the filter mounted in an airbox to get anything like a ram effect at speed -- which is exactly what some people do.

 

[mechtech]

The length of the intake will alter the torque curve due to resonant tuning, hence the 'ram' effect name.
It's not really an intake manifold, either.

 

[moribundman]

Of course it's not an intake manifold. It should be universally called "Saugrohr," which makes a whole lot more sense.

By your definition, any intake is a RAM intake, since resonance is inherently a factor. So, what do you call an air intake with a big, funnel-shaped, oversized opening that is located, for example, in the bumper, which will at higher speeds force more air into an intake? RAM-RAM air?