Home page
SPONSOR AD

Support our Vendors!  |  Advertise Here

Topic: Oil question.

in Forum: C4 Engines


Already a Member?
Login
Not yet a Member?
Register for Free!

Oil question. (1/8)
 4/14/11 2:51pm
scsjb02
Standard Member
Send Private Message

Joined: 11/23/2010
Posts: 17

I am doing some spring time maintenance on my newly acquired 91’.  The previous owner used 10w-40 oil.  I know that it isn’t recommended according to my manual.  Should I switch to 10w-30 or 5w-30 when I change the oil?  Looking for some advice.  Thanks

Our Sponsors help support C4VR
Oil question. (2/8)
 4/15/11 8:40am
sundew
Standard Member
Send Private Message

Eagan, MN - USA

Vette(s):
1994 Admiral Blue LT-1, Automatic, Black Interior; 1974 coupe, red, numbers matching L-48 4-speed; black interior


Joined: 1/25/2010
Posts: 41

My suggestion is to follow the owner's manual instructions. The folks at GM know a heck of a lot more about oil than I, so I stick with what they recommend.
Oil question. (3/8)
 4/15/11 11:50am
blacksharkL82
Standard Member
Send Private Message

Spring Hill, FL - USA

Vette(s):
1992 coupe. Custom.


Joined: 8/9/2010
Posts: 59

Based on where you live, oh, you didn't list it
Oil question. (4/8)
 4/17/11 1:48pm
redvette89
Standard Member
Send Private Message

Huron, OH - USA

Vette(s):
1989 Red Convertible - 160,000 fun-filled miles -


Joined: 12/5/2009
Posts: 179

Mobile 1 5w-30 is the only oil ever put in my '89 Vettesince it was brand new and after 150,000 miles, it is still running strong. IMO, the 5w covers most of the country since it's frequently below 70 degrees outside when the engine is cold. The 1st number represents the cold side of the oil viscosity and plays a roll in how well the oil gets to all critical parts when the engine is fired up from a cold start.

______________

 

Oil question. (5/8)
 4/17/11 3:32pm
Drew
Standard Member
Send Private Message

Newnan, GA - USA

Vette(s):
1991 Corvette Arctic White with Black GS style wheels Over 229,000 miles!


Joined: 1/11/2010
Posts: 15

My '91 has had only synthetic including Mobile 1 and Royal Purple. 5W30 works fine. Also, I've treated with Slick 50 (PTFE) years ago and in the last several years with Z-Max. 

It has over 230k miles and going strong.

BTW, I'm curious to find out how many people have put that many miles on a Corvette...
Oil question. (6/8)
 4/18/11 7:07am
eddie20890
Standard Member
Moderator
Send Private Message

lanoka harbor, NJ - USA

Vette(s):
1990 L-98 white/ red/black leather interior targa top auto 1975 L48 blue/black leather interior t tops auto


Joined: 3/22/2009
Posts: 1363

as with anything i always go with what the manufacturers call for. they design the engines using what they list and ithey should know what they are talking about. doesn't matter whether it is regular oil or synthetic the recommended is the best in my opinion. and with anything brand names are personal choices,

______________


















the dynamic duo


c3vr life member #97
Oil question. (7/8)
 4/29/11 2:36am
evilram
Former Member

Send Private Message

Chino Valley, AZ - USA

Vette(s):
Sold, sniff...1985 Cpe. White wlsaddle leather, 4+3, L98, Z51. Oh well..


Joined: 4/12/2011
Posts: 23

Hi , the old mechanic here.. My present '85 Vette 4+3 probably didn't specify Mobil One back then, though the previous owner used it since the owner before him and claimed it was fine..
I use Mobil One 5w30  in my wife's 2010 Terrain, with the Ecotech 2.4-Dir.Inj, VVT, H.O. 4cyl, but it's under warranty, and of course, it's my wifes' so.........
Anyway, my vette now has 167,000 miles on it.  Autozone had Mobil One in 5w30, but had Valvoline Full H/D synthetic in 10w30 so I bought that and changed it that way.. (with a Fram Tough Guard Filter) and a new plug gasket.
In my day, with that many miles, I would have gone with much heavier Castrol GTX 20W50..or later with Castrol SynTec 20w50...
Also I've been told if the car has used synthetic oil for a long time and switched back to regular oil, seal leaks develop.   Either way, I still feel uneasy planting the gas pedal with "piss thin" 10w30 oil on a high miles engine, even though synthetic.. What about adding STP oil treatment to it (showing my age again??)
Open to comments.. Thanks to you all..
Oil question. (8/8)
 4/29/11 6:50am
eddie20890
Standard Member
Moderator
Send Private Message

lanoka harbor, NJ - USA

Vette(s):
1990 L-98 white/ red/black leather interior targa top auto 1975 L48 blue/black leather interior t tops auto


Joined: 3/22/2009
Posts: 1363

joe,
believe you may have the questions of leaks backwards. i have heard that leaks will show up more likely if you switch to synthectic.
as with the weight of the oil, i would maybe check with gm about changing it up to 10w-30 as there have been a lot of new technology available and with you using synthetic oil already it may not be necessary to change what they recommend. my 90 has on it 139,000 mi and goed like a bat out of h..l.


______________


















the dynamic duo


c3vr life member #97
Our Sponsors help support C4VR