Damon B.

I just recently switched from 5w-30 to 10w-30 and I like the way the 5w-30 felt better. But the thicker weight is better for your turbo seals correct? What would be so wrong with mixing half of 5 and half of 10? Would they mix or would it be 2 seapreat liquids? (like oil and water trying to mix)

ekb18c

i used even thicker. I use 20-50

brian b

i know a guy that siezed his motor with 20w50... i dunno what the details are though.. im using valvoline vr1 20w50 and it works fine

Turbo00

i just heard that 20w50 was to thick and it wouldnt get through the bearings. i also know someone who seized using 20w50. for a race motor its fine from what i hear but for every day driving its not good.

DLB1994

i use 20-50 to

TurboSedan

10W-40 should be plenty thick enough for hot weather on a daily driver.

Damon B.

So can you mix oils? That was my origanal question, I am no where close to using 20w anything, I don't need to know about that.

Eric J

It's perfectly fine to mix different oil weights, as long as you keep the brands the same.

I would personally never run 20W-50 molasses in a Honda motor also... especially in the winter time. JMO

greyzone

mixing different weight oil is not a good idea...dont do it...seriously. And actually (if you had to) its okay to mix different brands, as long as you keep the weights the same...

just out of curiosity, why would you want to?? Is it just because you have extra oil or some other reason?


[Modified by greyzone, 10:49 PM 12/31/2001]

Damon B.

kinda, but I like the way the 5w feels compared to the 10, Is it ok to run 5w on turbonetics seals? even though drag recomends 15? Whats so wrong with mixing oils of diffenrent weight but the same company?

greyzone

The reason why not is a good question, Ii dont know the answer...i'm going off what Ive been told by very good mechanics and shops...I'll ask them tomorrow and see what reason they give for it...maybe someone else knows?

TurboSedan

I have never mixed different weight oils, and I do not recommend it. If you want 5w weight oil, change out the 10w **** so you know there will not be a problem. WHy risk anything right?

Damon B.

ttt

Eric J

All mineral oils are produced from the same basic petroleum feedstocks. Different oil viscosities will not separate or react negatively to each other because the base oil is molecularly the same. It's the different oil additive systems between brands that shouldn't be mixed - if you're concerned about the oil performing exactly how it was designed.

Oil additives include:
Anti-oxidants to prevent thickening at high operating temperatures.
Pour point depressants which lower the temperature of wax coagulation
alkaline materials to neutralize acids formed during combustion.
Rust and corrosion inhibitors.
Detergents to reduce sludge and varnish.
Dispersant additives to hold contaminants in suspension.
Extreme pressure additives to prevent metal to metal contact under high loads.
Viscosity index improvers in formulating muilt-grade (viscosity) oils.

The exact type and amount of these additives varies between brands and when mixed may not function as efficiently as desired. Different viscosities of the same brand oil will have different amounts of viscosity index improvers (polymers), but otherwise the additive systems will be the same.

From the Chevron.com site:
"Can I mix different viscosity grades of motor oils?"
"Yes. It is always advisable to not mix motor oil brands, however, different viscosity grades of the same brand motor oil are compatible. Be aware that mixing viscosity grades will turn out a product that is different in viscosity than either what was originally in the engine or what was added."

From Shell.ca:
"If you mix viscosity grades such as a 5W30 low-viscosity oil and a 10W40 higher-viscosity oil, it is reasonable to expect that the resulting product will have viscosity characteristics which are thicker than the 5W30, but thinner than the 10W40. This change does not reflect incompatibility - it's simply a re-balancing of the viscosity characteristics. In all other ways, the product should work as expected. But there's absolutely no danger about incompatibility resulting from mixing engine oils," Miller says. "We've tested all of our grades and brands, and we haven't observed any problems."

From Mobil1.com:
"For our customers to choose a viscosity grade, we recommend they follow the engine manufacturer's recommendations as indicated in their owner's manual. There is no need to mix two Mobil 1 viscosity grades when one will do; however, we see no problem mixing different SAE grades of Mobil 1 Tri-Synthetic series motor oils."

I agree that mixing oil viscosities isn't really necessary though. 5W-30 is going to have the same viscosity as 10W-30 when the oil is hot... might as well just use 5W-30 for its cold temperature "flowability". So the viscosity mixing argument is kind of pointless

greyzone

Damn dude, good, solid, throuough explanation and I sit corrected....thanks for that info.

Humbly,

Greyzone

Damon B.

Yeah, that was good ****. So here's a question, will 5w-30 be bad for my turbo seals? Will it be to thin? If there is no harm in using 5, I'm going back to 5.

greyzone

10-30 is recommended for turbos....

if you use 5-30 it will be slightly thinner at startup, both will have the same thickness when hot, which is the important issue with FI anyway

what type of difference are you noticing between the two??