wildman378

I've always used the 5w30 and the manual seems to recommend that overthe 10w30 but I talked to a guy today he said 5w30 was too thin to sun in the summer. I changed my moms oil yesterday in her manual i think it said anything above like 60 degrees use thicker oil all the way up to 15w40 if it can reach 100. This was for a 98 bmw 528 i. But in our manuals it seems like on that chart 5w30 should be ok during warmer weather but should I switch to 10w30 just in case?

thanks

flyersfan1088

Since the car came from the factory with 5-W30, and the manual specifies it, I would say it's fine.

Midnite 88

Since you are talking about a multi-viscosity oil, the 10w-30 should be fine.

The owners maunal of my wifes '96 Olds Aurora which has a 4.0L DOHC V-8 specifically states "do not use any other oil than 10w-30" it can cause engine damage. Something to do with the OBD-II engine control system.

Corvette Kid

I would and I did when my engine was stock. Now it's set up with looser clearances than from the factory and I use 15-50 Mobile 1

VettBrat

My 86 has 96,000 miles. I changed to 10W30 this summer and my oil pressure is running about 5 psi higher. I would say it probably depends on how "loose" your engine is from wear.

redwing76

5-30 is to thin for warm weather.
BMW has stopped using 5-30 in the M-3 due to engine losses, some 100 to date. They now reccomend 10-30.

Oil temps run 50-70 degrees higher than coolant temps.
A coolant temp of 200 degrees nets a oil temp of 270 degrees.

Non synthetic oil runs into problems at 270 and the life of the oil and its lubricating abilities considerably reduced.

Synthetic oils can survive up to 350 degrees.
The way that muit grades work is some 20% of thier volume is a plasticizer, as the oil temps go up the plastic stretches creating the higher viscoisty.

But at cold temps the plastic is dormant.
Unless you see a lot 0 temp days I'd avoid 5-30 or even the new 0-30.

In a 92 and later I'd stay with the Mobil 1 10-30.

wildman378

Ok, thanks for the replies. I just had changed mine with the 5w30 too... CRAP...now if I drive it I'm gonna feel like it's gonna blow the motor HAHA. Jokeing but I think I will go to 10w30 next time I change it in warmer months.

vader86

Every old mechanic will tell you to never use 5w30.

Use it during winter if you want, I did occasionally. I use 10w30 or 15w50 during summer now.

Corvette Kid

Hey, I resemble that remark! Yes, I wouldn't have a problem with recommending 5w30 for winter particularly in the colder climates, in fact I would recommend it for extremely cold ones. Here in NC we seldom see teens, even at night and I will probably go back to the 10w30 for those months.

SunCr

Use it in the Vette and every GM I've owned over the last 20 years with no problems. I can't remember a single post on the forum involving an engine failure or problem due to oil vicosity; nor a service bulletin, recall from any of the OEM's, any complaints at the NHTSA web site and if all the SUV's and Soccer Mom Vans had a problem with it, don't you think there might have been a blurb somewhere? Rumor had it that GM had issued a Bulletin recommending that the LS1 owners switch back to dino; couldn't confirm that either. Use what pleases you, within reason of course.

corvettemaster

i've always used 5w30 like the manual recommends in my 86. and the manual for my 98 cavalier recommends 5w30, but also states i can use 10w30. i just changed the oil in both this past weekend, and used 5w30 in each. i've never had any problems. i live in kentucky and it was 90 here today. should i change to 10w30?

vetterlatethannever

I went to 10 30 once for the first oil change when I got my car and the oil pressure meter would peg out when the car would reach moderate RPMs(2500-3500) when cool(under 150 degrees). Ran fine once the engine warmed up but the next oil change I went back to the 5 30.

Corvette Kid

With the tighter tolerances of modern engines they are, of course capable of (and should use) lighter oils than in the past, without problems. This being said however I think most of us here on the forum assume that we generally run our cars a little harder than average and so a little heavier oil, without going overboard is just a little extra insurance. Believe it or not, one of the original reasons for manufacturers recommending extremely light oils was and still is to improve their corporate average fuel economy numbers, not because it is the absolute optimum oil for a given engine. Like with many things, it became a necessary compromise.

mitymek

not this one. i never recommend thinking you know more than the manufacturer.

an enlightening thread from the c6 forum http://forums.corvetteforum.com/arch.../t-847002.html

seems things havent changed much in the generals war room on the lube of choice topic.
im stickin with what it says on the cap.

mitymek

not this one. i never recommend thinking you know more than the manufacturer.

an enlightening thread from the c6 forum http://forums.corvetteforum.com/arch.../t-847002.html

seems things havent changed much in the generals war room on the lube of choice topic.
im stickin with what it says on the cap.

and also (editing),even in the old dino days of thunder,5w30 would be the same viscosity at 100 deg f. ambient temp as 10w30,or 15w30 wouldnt it?
i think if your concern was your oil being thin on hot days then you would want to increase the second number not the first.
pretty sure once things are warmed up its all just 30 weight oil unless you put in xw40 or xw50.

silver84

If you make seasonal oil changes, you might
want to think about 10w-30, over 5w-30, cuz,
10w-30 probably uses less VI extender, so more of the
'oil' is base oil.

wildman378

All good thoughts, seems like it's about equal on what people think about it being too thin.

After reading some of your responces and readng up on it a little I don't think the 5w30 is a risk at all really but I see no problem with the 10w30 either I don't think thats going overboard so either seems fine to me. I just always kept hte 5w30 because it seems to recommend it a little more over the 10w30 for most driving conditions.

newbecorvetteguy

I just bought 5w-30 for my car. It better be ok since that's what it says to use in the owners manual and on the oil cap on the engine. That is lighter than I've ever used before, but if that's what it says to use, that's what I use.

redwing76

www.mobil1.com
http://www.northstarbmw.com/newslett...00/october.htm (more than you ever wanted to know about oil)

Biggus Blockus

OK, I've run Mobil One 10w40 in my 94 for some time now (summer only). It made very little difference in my oil pressure readings except at startup (60 lbs or so).

I picked up a couple of 5 qt-jugs of the 15w50 at Wal-Mart the other day and am thinking of using it next oil change (once per year - car sees 2000 miles of summer use then sleeps over the winter).

Any concerns I should be aware of?