Is it OK to mix oil weights in an engine?

[JDM_Hatch99]

My

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[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?

[rick2130]

mixing oil? why not as long as they are the same manufacturers/brand or mil-specs, basically your just change the viscosity of the oil! but when you mix oils with different manufacturers/brand or mil-specs you will risk your engine! because different manufactures use different additives and etc. even though they have the same mil-specs

[Mike]

I never use 5w-30 in california…too thin…oils are tested in freezing temperatures. How often do you drive in freezing temps?

[joescorpio]

any oil is better then no oil.just change it to what the cap says when u can.

[JDM_Hatch99]

Yea the oils were the same brand and type neither different weights. And it doesn’t often drop below freezing here.

I have religously stuck with valvoline for years now, but do you guys recommend a different, better brand (non synthetic)?

[joescorpio]

seriously? they were on a rant about mixing weights for hours. you did say you used different weights in the beginning..and you only wanted to know the best brand or weight to use? just sayin

[EricTheCarGuy]

Well this has turned into a lively discussion, my complements to everyone for keeping the discussion a discussion and not an argument, I think that’s testament to the people on this forum, in short, you guys are great.

As for my 2c well I’ll start by saying that just topping off with 10W30 is way better than not topping it off at all and I don’t feel that if the oils are different brands it will may any difference at all. So to answer your original question I don’t think that would be a problem, in fact most oils out there have the same API rating these days which is the most important part of the oil rating next to it’s viscosity in my opinion.

That said as far as my experience with Honda’s go it is as follows. High mileage Honda engines and even some low mileage engines especially the 4 cylinder models WILL burn oil normally, in fact it works out to about a quart every 3000 miles which is what some have stated in this forum. This is accelerated if you drive at high speed for prolonged periods of time like say you drive 80mph on the highway for a few hundred miles this oil burning will increase and is normal from what I’ve come to find. I believe the reason for this is the increased cylinder pressures created by high speed driving.

Now a word on viscosity. Personally I don’t like to go outside of what the manufacturer recommends especially with an overhead cam engine, the reason is that in colder weather the ‘thicker’ oil will take longer to reach the top end thus increasing the potential for wear on the top end parts. I’d rather be topping off my engine from time to time, in fact I keep a spare quart of oil in every vehicle I drive, than use a thicker oil to try and compensate for noise or oil consumption, to me this just makes the problem worse and driving around with a spare quart of oil and checking the level on a regular basis seems like a small price to pay.

Lastly I don’t use synthetics in things that don’t call for them, I buy cheep oil with the latest API rating and change it religiously, this has served me very well over the years and I’ve had no major problems with any of my engines as a result in fact the one I took the farthest was my 91 Integra which had 326K on the clock when I gave it to my 17 year old son who ended up killing it about 3 months after that because he was being a stupid 17 year old in a 91 Integra with 326K on it, he regrets this I can tell you because now he drives a 2000 Intrigue.

I hope my comments add something to this discussion but understand that they are based on my experience and are my opinions I know a lot of people have differing opinions and I respect that, in fact I even brought it up in the first video that I ever posted as ETCG.

http://www.youtube.com/watch?v=_MQo_Xmkchg

[hbvx]

^Totally valid and great contribution. Right on with your experience! T)

The reasons Eric stated is why some vehicle; for instance driven on the autobahn compared to NA speeds, may need a bump in viscosity(nothing crazy, 1 grade) IF seeing prolonged high speed driving. Of course that is by choice. Just like it’s a choice to race your vehicle at a track, guys get add on oil coolers for a reason. If the oil sees hotter temperature, aside from a potential ‘consumption’ standpoint, you ‘will’ have a degree are shearing and your HTHS(High Temperature High Shearing) rating as well as basestock quality are ‘huge’ for extreme racing.

Red Line is big in this area, they produce PCMO that has higher HTHS than most anything else in the ‘same’ grade without having the specs of a HDEO(not HDD, but one that dual specs API for diesel and for gasoline).

Just to be clear: I am not a thicker is better guy, just only as thick as necessary. As thin as possible(usually in NA you are given the lowest possible after those extensive tests in order to meet CAFE requirements for one, but thats another discussion, I dont think if driven like a stop ‘n go sane person will ever be an issue using the manufacturers recommended oil).

[Author]

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