Is it OK to mix oil weights in an engine?

[JDM_Hatch99]

My

Topic

[Matt]

At startup, the higher weight oil can cause some oil starvation. I would switch back to the recommended weight oil as soon as you can. It won’t blow up your engine right away, but you never want to get away from the proper lubricants, ESPECIALLY engine oil.

[hbvx]

Absolutely not. (last edit: this was in response to the OP and directed at the OP)

There are guys out there blending their own mixture like oil geeks/nerds for desired HTHS(at least ‘initially’) but more measurable might be the relative VI from starting ambient temp to full temp, the only thing that matters is if your service type changes.

I would step up to a 40 in an ALL OUT racing condition for most Civics of older vintage which ran 5w-30 as the norm.

For street driving, 0w-30/5w-30-/10w-30…it’s all the same(CLARIFY: at operating temp). Some domestics and very specific apps can be ‘picky’ at startup but MOST cars don’t need their oil to be ‘as thick’ as a 10w-30 is at COLD startup compared to a lighter 0w-30.

I use 0w-30 synthetic, it doesn’t matter though. It’s a SAE 30 at operating temp. Honda’s are usually so easy on oil, mixing any brand name oils for similar API rating(if possible but even that won’t napalm your engine lol), but more so their viscosity rating is most important.

An example of a popular blend outside of different viscosity:

http://www.bobistheoilguy.com/forums/ub … 326&page=1

So, your 10w-30 + 5w-30 really isn’t outside any realm of sanity.

[Matt]

Quoted From hbvx:

Absolutely not.

There are guys out there blending their own mixture like oil geeks/nerds for desired HTHS(at least ‘initially’) but more measurable might be the relative VI from starting ambient temp to full temp, the only thing that matters is if your service type changes.

I would step up to a 40 in an ALL OUT racing condition for most Civics of older vintage which ran 5w-30 as the norm.

For street driving, 0w-30/5w-30-/10w-30…it’s all the same. Some domestics and very specific apps can be ‘picky’ at startup but MOST cars don’t need their oil to be ‘as thick’ as a 10w-30 is at COLD startup compared to a lighter 0w-30.

I use 0w-30 synthetic, it doesn’t matter though. It’s a SAE 30 at operating temp. Honda’s are usually so easy on oil, mixing any brand name oils for similar API rating(if possible but even that won’t napalm your engine lol), but more so their viscosity rating is most important.

An example of a popular blend outside of different viscosity:

http://www.bobistheoilguy.com/forums/ub … 326&page=1

So, your 10w-30 + 5w-30 really isn’t outside any realm of sanity.

I don’t agree with this. It’s not all the same. Manufacturers recommend oil weights based on ridiculous amounts of engineering, not ‘ALL OUT’ racing. The first number in an oil, like the 5 in 5w30 is the oil’s viscocity in Winter, or on a cold start. Ignoring that number and just putting whatever in there will lead to oil starvation at startup, and severe engine damage over time, especially if you move to a thicker oil.

[hbvx]

^I didn’t say that, you read that wrong or simply didn’t get the context or flow of logic in the post.

Let me be clear: There is no need to change oil ‘grade’ unless your service conditions were to be outside of the norm for PROLONGED periods of time(racing at a track for 2 hours near red line) and then you just might want to consider bumping up a grade. This has been beaten to death so many times over at BITOG.

It’s about first the vehicle, and then service conditions seen.

A Honda is ‘easy’ on oil. (ADDED: at least my app is. Most Civics are as well. Si I can’t speak for, but their SOHC engines are very easy. The OP, I initially thought he was talking about a Civic(not familiar with his vehicle, need more info).

BTW, what year Integra is the OP driving?

Yes, go by the vehicle manufactured specifications. My post wasn’t to change your grade of oil, but to show ‘blending’ isn’t going to bomb your engine. Guys are doing this right now, getting analysis, for thousands and thousands of miles with no blown engines. Don’t follow this out of ignorance(as the OP is obviously new to oil?), though. A ‘little bit’ of 10w-30 to top off of 5w-30 is basically NO change.

30 is what BOTH are, essentially. The first number ‘only’ signifies ‘how thick’ at startup the oil is. It’s a 30 at full temp. Thicker at “startup” temp than necessary is a key in using the first number as a guide only.

5w-30 and higher VI oils of times past(15-20 years ago) were not as solid at covering this VI(Viscosity Index), poor VIIs(Improvers to the VI) and the shear stability of this oil basically kept 10w-30 the norm for a while. This after straight grade was only available for years, and so forth as oils have advanced with the advancement of technology.

Even today some swear by it, but the truth is most cars don’t need 10w-30 that used to be spec’d for it. They could use 5w-30 is available to them or even 0w-30 at that point. It depends on the oil in question, and how it’s characteristics define itself as more suitable or not. Some domestics are picky.

Just like oil filters, some apps are picky and will have startup noisy during cold starting.

*EDITED

[Matt]

I didn’t read it wrong. You essentially said the first number in the viscocity doesn’t matter, and it absolutely does. If your vehicle calls for 5W30, use 5W30. Don’t throw out that the first number means nothing, because you will cause oil starvation at startup, as I stated. I’m not sure why you are arguing that fact. It’s well and good that the second number is fine, but the most wear on an engine is at startup, when the engine is already mostly cleared of oil, and if you add a heavier weight oil (the first number) you will cause excessive wear when you start the vehicle, because if it’s too thick, it takes longer to reach the top of the engine. The only exception would be if you lived in extreme high or low temperature climates, and the vehicle’s owners manual will cover those circumstances.

[hbvx]

^sigh…we’re burning the same candle on both ends.

I even stated that I use 0w-30! lol.

So how is it that I’m suggesting ‘it doesnt matter, just run straight grade 30’. I didn’t mean it to be taken that way and I wasn’t clear and I since fixed it, my apologies.

It’s all good, just passionate here. T)

You won’t have ‘oil starvation’ to an extreme extent, just ‘better and better’ as you get closer to a better flowing/easier flowing at startup oil. He was talking about TOP OFF OIL. 1 quart added to 4 of 5w-30 is still different at startup flow than a sump full of 10w-30. Cranking ease(there are two different characteristics for oil regarding temperature and flow, one is relative to ‘pour point’ and another is relative to ‘cranking resistance’) Some oils have the best of both worlds. Some synthetic 0w-20 has a greater cranking resistance than a thinner at startup 0w-20 which because of ‘formulation’ has more ease of cranking.

Mobil1 AFE 0w-20 and one of Toyota’s 0w-20 oils are very similar, but Toyota’s basically ‘resists’ thickening up as quickly once you pass freezing as all oils will thicken, their rate and such is completely formulation dependent. The viscosity labeling is a good guide, but that stops there. If we’re getting into what’s best for ‘absolute’ lowest startup wear. Read the thread I linked in my Previous Post.

AND as engine oil is used, it will thicken up from use in some apps(oxidative thickening) and the ‘typical properties’ as brought out on pds regarding an oils ‘characteristics’ at startup, which go beyond the labeling on the bottle as previously mentioned.

For instance, HTHS will not still be what the virgin spec ‘claims’ or perhaps ‘is’ after use. Shear stability and the robustness in base stock quality/type or source, of any name brand oil these days; especially a good 0w-30 like relative to the OP, is all that most PCMO lubricated engines that are street driven need in the US or CAN need. It’s relative to location some, use seen more.

Now, these same cars in Germany on the autobahn would absolutely have different ‘recommended’ oil grades.

ADDED: I’m just passionate here and felt I was misunderstood responding initially after the OP’s comment. I have no problem with Beefy outright, lol. This is just about oil(and my addiction), /endrant.

[joescorpio]

yoda says please be nice to each other on posts just sayin

[Matt]

I’m not trying to start an argument bud. I guess I misunderstood your posts. I’m just trying to get my point across that you should stick to the suggested oil specs, because I doubt the guy is racing his Integra. It’s all good. But his ‘app’ seems to be a normal car, and while I agree that adding some heavier oil here and there won’t explode his engine, I would recommend getting the correct viscocity back in as soon as is convenient. And I’m done.

[hbvx]

^My apologies for sounding like a jerk if that’s how it came across? It’s late, long day. We were on different ends of the same stick. T)

…and yes, I have problems being too defensive. Without your response I wouldn’t have seen how I did in fact state it wrongly and left it open for interpreting. Thank you. This is my problem, sorry Beefy…W-|<---Yes, I do this sometimes. To me, it's relative though. It won't hurt measurably for him to add 10w-30 for now as top off. At least, the 'variable' of 'increased startup wear' isn't catastrophic by any means, the engine isn't under and increased load aside from the greater resistance of thicker oil, which ALL oils are 'too thick' at startup in essence, but some engines have larger tolerances when cold vs a car like a Honda, and 'prefer' 10w-30, which is why I specifically stated some domestics are 'picky' and don't like thinner oils. I can think of one: Chevy S-10, GM 4.3 vortec seem to like 10w-30, at least if you go by idle oil pressure. Some filters can help this, but servicing my dad's vehicle and also running into the LIM gasket leaking coolant into the oil is anothe reason to consider 10w-30; I'm probably going to use 10w-30 Rotella T5 HDEO to resist the effects of coolant in the oil until he gets this fixed. That said, I do agree it's pointless to step up to 10w-30 as well in most situations. In fact, depending on the recommended factory specs, if it allows for 5w-30 'preferred', just use 0w-30 full synthetic. the end, or 5w-30 conventional. I can recommend quite a few number of brands too. Majors are good, sub-brands under those are still good as well. Mostly avoid rest stop oils or gas station oils and you are good. In fact, here is a site that has posted tests of various grades/brands/API-spec oils vs what they should be, hope its useful or interesting: http://www.pqiamerica.com/

[JDM_Hatch99]

Yea I was going to switch to 0w30 for ultimate “flow properties”, but since the teg burns oil I figured it would just burn more. I’m already burning a quart every 3000-3500 miles.

[joescorpio]

its really a choice you have to make, using a heavier oil will burn slower but its just a bandaid adding thicker oil will not fix the problem just slow it down and possibly give you a diiferent problem

[hbvx]

Quoted From JDM_Hatch99:

Yea I was going to switch to 0w30 for ultimate “flow properties”, but since the teg burns oil I figured it would just burn more. I’m already burning a quart every 3000-3500 miles.

Mileage? That’s what my old Civic uses every 3,500. It was worse when we first got the car 30,000 miles ago.

Here is a tip to always remember:

Changing oil types/brands(outside of ‘viscosity’ as the OP is about) ‘may’ cause a consumption rate change initially for any vehicle in any condition. Give it time, monitor consumption, it ‘will’ stabilize unless for some strange reason a neglected or simply ‘aged’ vehicle has a gasket that was close to letting go and the formulation change alone had a coincidental or not relationship with the seal failure.

It’s almost like shock treatment in a sense(relative, not seriously in a bad sense;generally speaking), on the engine’s internal ‘identity’; which is a reflection not just on service seen, but on it’s interval and oil type as well as fuels used, etc.

For example, 150,000 miles/10 years on oil type ‘A’ (lets say conventional) will have different characteristics when compared to an oil of type ‘B’ (A synthetic oil of a high-end quality or formulation, perhaps with vastly differing detergent add pack alone let alone base stock quality improvements etc)

The key is establishing some known variables. Lets say this was a SOHC Civic that was not abused, but went anywhere from 3,000-6,000 miles between oil changes using name brand conventional. Of course, conventional of 2012 is much better than conventional of 1992. Some might counter-point that so are todays fuels, but in a bad sense for vehicles not designed to use ethanol at the percentage e-10 has it, thus effectively reducing fuel economy in a car…like mine…

Anyway, lets say for sake of the discussion that the engine didn’t have ‘sludge’, perhaps some metal staining and discoloration but not much depositing, never overheated the works. etc.

Switching to an oil of radically different formulation may cause consumption to spike for a while.

IMO, your consumption rate is normal for a high-rev Honda ‘relatively speaking’.

[OnThe7ThDayFord]

Im going to say it depend on the oil.

I had a Mitsubishi eclipse that i got with 30k on it and drove it to 233k. Around 233k every morning i would start her i would get blueish smoke out the tail pipes so I started adding valvoline racing oil (its 50w) to stop the oil from leaking around the valve seals. This helped.
I think the car took 5 qts so I added 4qt 10/30 and one 50w of val every oil change. anyway she drove fine like this to 340k when i soild her.

And i hotrod the living hell out of this car.

[hbvx]

Quoted From college man:

I would not mix oils. you don’t know what your creating. just use what the manual says.C8-)

For most people, this is true.

However, you can ‘more peace of mind’ safely blend two oils of the same brand and type; for instance 10w-30 and 5w-30 Quaker State Ultimate Durability(QSUD), and have the same oil just a ‘slightly’ different bottom end range as far as how easy it is the start, the end.

That way, you aren’t guessing at the add pack of varying brands.

However, even companies say mixing is harmless these days; especially oils within the same family of API rating or simply oils of the same brand/type. Mix away.

OTOH, ‘most’ tend to agree it’s better to stick with ‘as much’ of one than trying to outright ‘blend’ oils to make your own without really knowing what you are doing. (and of course its only an educated guess and more ‘out there’, I’m just showing that somewhat ‘extreme’ sounding example should reflect on blending essentially the same oil[brand/lineup] of two varying grades).

Only a few guys are doing this as tribologists, the apparently ‘extreme’ mixing. I used some examples previously only to show how two radically different oils put together as far as viscosity range and even perhaps add-pack is not unheard of or something terrible. It helps to know who supplied the oil to dealer labeled, relabeled oils. Some are rebottled, others are slightly different formulations.

I forget if it’s so, but XOM makes both Toyota 0w-20 and of course the M1 Ow-40, both are very popular for good reasons. Blending at the right ratio of each using viscosity calculators will net yield a robust 0w-30 oil with a higher HTHS and VI than; for example, Mobil 1 AFE 0w-30 while still keeping awesome cold start characteristics compared to conventional 5w-30 and 10w-30. Since it’s made by the same formulator, the basestocks are of similar quality and characteristics with their own unique advantages in of themselves. Most agree no need or point in blending 1 quart of this or that, etc. Stick with the same formulator or blender at least, that is basically childs play at that point, IMO. The other is pointless and you aren’t getting the best of any oil straight up with varying brands alone.

[JDM_Hatch99]

Quoted From OnThe7ThDayFord:

Im going to say it depend on the oil.

I had a Mitsubishi eclipse that i got with 30k on it and drove it to 233k. Around 233k every morning i would start her i would get blueish smoke out the tail pipes so I started adding valvoline racing oil (its 50w) to stop the oil from leaking around the valve seals. This helped.
I think the car took 5 qts so I added 4qt 10/30 and one 50w of val every oil change. anyway she drove fine like this to 340k when i soild her.

And i hotrod the living hell out of this car.

wow 340K out of a DSM?? thats definitely a world record…must of been the non-turbo model?

[Author]

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