which oil is best????

[beantown04]

I just got an oil change and they put in 20w/50 is this good or are they crazy???

 

[NRRfrogmanP5]

isnt it supposed to be 5w30? or maybe im wrong

 

[mogi]

I usually run a 10w30 or 5w30 in mine, I don't think I've heard of anyone running 50 in a P5 though...

I do remember a thread a few months ago about dealers switching to something else though, can't remember off hand what it was

 

[LinuxRacr]

I ran 20w50 Redline oil for about a year and a half without an issue. That's the thick s***.

 

[beantown04]

I ran 20w50 Redline oil for about a year and a half without an issue. That's the thick s***.

Im a little nervouse about pressure, if the oil doesn't thin out will I have a problem?

 

[i12drivemyMP5]

Been running Castrol Syntech 10 - 30 since 3000 miles. Tried Mobil-1 once but Syntech seemed to survive better. Stayed more like it did out of the bottle than the Mobil-1 did. Used same oil filter, same air filter cleanliness, same driving habits. I run K&N air filter, purolator micronic filter for probe GT because it is a little longer than the P5 & change every 5k give or take a little. Have had no issues. Not saying this is any better than another, just is what I used & the car seems to like it......

 

[mogi]

<-- Amsoil ***** over here! I have amsoil tranny fluid and run amsoil motor oil. I'm taking a big jump and testing out their 1year/25k mile oil change interval...

 

[Protege52003]

i have been using 5W-30 since day one.....mobil1 and have had no trouble. you can use 10W-30, too........

 

[gino]

Not sure why anyone's running 20-50 unless you're spending a lot of time on the track; 5/30 or 10/30 should be more than adequate if the engine's not showing signs of ring wear.

Running Quaker State "Q" 10/30 synthetic with no probs.

 

[LinuxRacr]

Im a little nervouse about pressure, if the oil doesn't thin out will I have a problem?

The only reason I used it was in the summer with my forged internals when I first had this motor buil. Then I realized last year, I really didn't need it that thick. I only use 10w40 Redline now.

 

[RedP5er]

I just got an oil change and they put in 20w/50 is this good or are they crazy???

The thicker oil may not be able to reach tiny passages desgined for 30 weight. Oil starvasion may causes premature engine wear. If your engine is stock and the mileage is not particularly high, I would switch back to 10w-30 or 5w-30. My 0.02.

 

[YellowMP5]

you should be fine imo. i believe 10w30 and 20w50 should act absolutely the same at the same engine temperature. its when it gets much hotter that the 20w50 should have more protection. for the same reason 20w50 offers less protection iirc when its cold out but since you are in florida (where?) you should not worry. i am in south florida and in 13 years that i have been here i am aware of only once that the temperature has reached 0 degrees in the winter.

 

[p5power]

i am aware of only once that the temperature has reached 0 degrees in the winter.

Once???? bastards those floridians i'll be lucky if its that warm in febuary. of course, those canadians have it even worse. i should really move to a more temparate climate...more time outside to work on the car!!

Oh, and I've been running mobil1 5w-30 for about 15k miles...seems to be doing the job well.

 

[RedP5er]

i believe 10w30 and 20w50 should act absolutely the same at the same engine temperature. its when it gets much hotter that the 20w50 should have more protection.

Not trying to be picky, but I have doubts about that assumtion. I am no expert in engine oil chemistry, but from data taken from Mobil's website, oil of different grades behave differently at the SAME temperature. Even for 5W-30 and 10W-30.

SAE Grade 5W-30 10W-30 10W-40 15W-50
Viscosity, ASTM D 445
cSt @ 40 C 57.3 66.57 91.07 133
cSt @ 100 C 10.25 10.5 14.2 18.2
Viscosity Index, ASTM D 2270 169 146 161 153
Sulfated Ash, wt%, ASTM D 874 1.35 1.38 1.35 1.42
HTHS Viscosity, mPas @ 150C ASTM D 4683 3.08 3.21 3.9 4.43
Pour Point, C, ASTM D 97 -45 -54 -42 -42
Flash Point, C, ASTM D 92 226 224 224 241
Density @15 C kg/l, ASTM D 4052 0.861 0.871 0.870 0.866

Correct me if I am wrong, but I believe thicker the oil doesn't always mean better protection at high temp. A grade 30 synthetic oil may have higher flash point than a dino oil of grade 50. Beside, as much as I would like it to be, our engine is not a high performance engine. It just doesn't produce that much heat.

Anyhow, I think 20W-50 will probably do no harm to the engine. I don't think our engine's tolerance is that high and 20W-50 should be able to pass through all the critical passages. However, I will stick with 5W-30 or 10W-30 myself. (drinks)

 

[p5power]

i'm pretty sure in the owners manual mazda suggests running either 5w-30 or 10w-30, depending on the ambient temperature range.

 

[beantown04]

you should be fine imo. i believe 10w30 and 20w50 should act absolutely the same at the same engine temperature. its when it gets much hotter that the 20w50 should have more protection. for the same reason 20w50 offers less protection iirc when its cold out but since you are in florida (where?) you should not worry. i am in south florida and in 13 years that i have been here i am aware of only once that the temperature has reached 0 degrees in the winter.

Thanks for all the input. I live in the Tampa area and it is hot as hell but I do a lot of driving back and forth to Boston so I think I will stick with the 5w30 at least untill I can afford a turbo!

 

[otmsp]

wd-40

 

[YellowMP5]

Not trying to be pick...

wow, very good research. glad someone did the legwork. apparently i am wrong. i always understood that oil weight numbers as more or less upper and lower temperature ranges (although numbers are not direct). thus i figured that different oils would act/flow the same at the same exact temperature in the engine. i guess i was wrong.

does anyone know what those abreviations actually stand for?

 

[RedP5er]

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=forum;f=1

Good board for those who want to know more about engine oil.

 

[Domspun]

<-- Amsoil ***** over here! I have amsoil tranny fluid and run amsoil motor oil. I'm taking a big jump and testing out their 1year/25k mile oil change interval...

hehe, me too, I used the 2000 Series 0w30.. mmmmmm... oil...