Gasp! 5W20 in 5W30 Car!

Status
Not open for further replies.
Joined
Aug 12, 2005
Messages
4,564
Location
NW Ohio
Changed the oil in my '00 Honda Accord V6 yesterday and installed 5W20 rather than the prescribed 5W30. I had five quarts of 2008 vintage 5W20 Castrol Syntec SM on the shelf. "Sounded" and "felt" the same after, not that I am worried. The 3.0L was back-spec'ed to 5W20 to 2001, and there are no changes in engine design that I could determine from '00-01. Also, the car is gently driven to attain maximum mpg.

The oil I changed out was a 10K run as well, on a blend of 4 qts GTX/1 qt Syntec with a P1 filter. Took a sample but dropped the sample container into the drain pan, so unfortunately, I cannot now UOA it. THAT was a distressing incident! Can autopsy the filter, tho, after it drains a couple of weeks.
 
Using correct oil viscosity seems to matter the most in extreme conditions.
For example, using a heavier oil than specified can have a negative effect on engine wear during situations where the oil is not fully warmed up, but high RPM, high load is applied because it may force the oil pump into the by-pass mode.
Similarly, when the lighter than specified, oil is used and the oil temperature is pushed to the max, the lighter oil may not have the film strength to provide protection.

So, since most people hardly ever operate in those extreme situations, the engine is very tolerant to a wide range of oil viscosities.
 
It will probably lock up just sitting in the driveway!
grin.gif
 
Originally Posted By: Jim Allen
Like I said, not worried in the slightest but was hoping for some entertaining replies.


I'm glad I don't know anyone that lives near you, the explosion of your engine will no doubt wipe out a 50mi radius...
 
Jim you are indeed an risk taker!

Trick question.
What's the viscosity difference in the base oils used in a 5W-20 and 5w30 conventional?
How many correctly answered no difference, they have the same viscosity? The only differnce in the two oils is that the 5W-20 uses less polymer thickeners.
Additionally as a group 5w20 conventionals use higher quality GP II and GP II+ base oils than 5w30's. So while their virgin viscosities are a grade apart (when it matters most for CAFE reasons) at the end of a OCI that difference is marketedly less or non- existent if you compare the best 5w20 conventional with the worst 5w30.
 
Jim, make that right immediately by switching that witches brew out to a good ol' American 10w40... which we all know is the only viscosity worth a dang
smile.gif
 
I did it in my 93 Aerostar without issue, but it will be going to the junk yard with Mobil 1 Turbo Diesel Truck 5W40 in the sump.
 
I run 5w20 in my EJ22 Subaru all the time. Coming up on 200K here in the next couple of months. Everyone says it's a bad idea but it's working fine. The used oil analysis have confirmed this as well as the fact that it's running better than ever these days. I know I have seen better fuel economy with the 5w20 that's for sure. Last year I ran 5w20 all summer and my best tank was 33.75. This year the best I have done is 30 with the 5w30. Looks like I need to find some more deals on the 5w20 since I'm down to my last 20 quarts. If not, I'll just have to suffer on MPG's since I still have over a 75 Qt's of 5w30.
 
Originally Posted By: mechtech2
10k on dino?


Depends. If you call Gp III dino... yeah. Otherwise it was four quarts GTX and one qt Syntec, a mix that has worked VERY well for me over about six years. As I said, was going to UOA but dropped the sample container into the pan (which was filthy). I had done an 8500 mile run on that oil with a good UOA so my presumption is that it was OK... but would have liked to have proved it. It wasn't real dark. Give me the Fumble-Fingered-FUBAR Award for September 12, I guess.
 
I run 5w20 in my 05 Altima VQ35 in the winter. I drive the car about 400 miles a month. Almost all short city miles.
 
Originally Posted By: sw99
Looks like I need to find some more deals on the 5w20 since I'm down to my last 20 quarts. If not, I'll just have to suffer on MPG's since I still have over a 75 Qt's of 5w30.

See if you can get a deal on some Toyota 0W-20. It's actually supplied in bulk now to dealers and one member mentioned having some 5qt jugs filled up for a song! You can mix it 50/50 to use up the remaining 5w30 in your stash. That will give you a heavy 190 VI 5W-20 that's just as light on start-up as a light 5W-20 with the added benefit (although not entirely needed) of a heavy 20wt like Amsoil ASM 0W-20 at operating temp's.
 
Originally Posted By: Jim Allen
Originally Posted By: mechtech2
10k on dino?


Depends. If you call Gp III dino... yeah. Otherwise it was four quarts GTX and one qt Syntec, a mix that has worked VERY well for me over about six years.


I like your mix but your post has me confused. Are you saying regular GTX is Grp III?
 
I ran 5W20 in my Toyota Tundra V8. I did a used oil analysis on it and the results came out good. The engine is back-speced for 5W20 according to Toyota's TSB.

Next risk: 0W20 in an 02 Chevy 1500 5.3L.
 
Status
Not open for further replies.
Back
Top Bottom