TVRPAUL

Does anyone see a problem of using 10W 3 0 or 10W 40 oil instead of the recomended 5W 30.

FireBirdKnight

its alot better to use in hot weather vs the cold it isnt

TVRPAUL

The reason I asked is because the new engines have much closer tolerances then the engines of old.

FireBirdKnight

it shouldnt effect anything except make a higher oil pressure

TomP

I've run 10W30 since I got the car in 1994 with 65,000 miles, the engine's at 291,000 miles now with no rebuild yet!

Toehead

some us us run 20w50! Myself, I run 15W50 Synthetic, which actually seems to be as thin as conventional 10W30 as far as pouring goes. I do this because I do a lot of summer highway driving and I like the protection of a thicker oil. Also, on startup, the pressure rises instantly and rapidly, so I am not concerned with dry starting.

daves12secV6

iTrader: (3)

im one of those that runs 20-50,in the dead of summe ri switch to single wieght castrol 50.do to the fact i make alot of 200 mile round trips down the the shore.
though now with the turbo ill be lookin ginto going synthetic but unsure of which wieght yet

Doward

15w50 M1 here

Toehead

Hey, I run the same oil as Doward! Now I know it'll work .

87BaseFirebird

i bought my 87 with a 2.8L. the owner always used 10W 40 conventional. My dad took it to a mechanic and he suggested synthetic, my dad agreed. Later that day the rod bearings broke and it will cost more to fix them than the car cost. The seller of the car said it was because you cant run synthetic in that old of an engine, is this true?

Hope this will help someone else.

FireBirdKnight

i dont think a switch over would do any harm im the origional owner of my 87 firebird ive used synthetic since ownership no problems

but on my sisters case she'd get what ever oil was cheap but sometimes she'd use a synthetic that motor lasted a good 189K before it craped out it was a 2.8 personally IMO i think that guy put 1040 in it to cover up some of the issues like possable "knock" or possable smoking

W72

iTrader: (9)

3 things I usually don't discuss; Religion,politics and motor oil 'cause everybody has an opinion and the conversation usually goes south on all 3.

But, I'm compelled...A bearing failure while running freshly installed synthetic is probably just a coincidence. No surprise the "seller of the car" feels differently.

It's my understanding that switching to full synthetic in an engine with,let's say, more than 30K miles is that you may develop leaks or make old leaks worse.But that's the only downside I know of.

I bought a truck with 45K with a 5.7 Vortec and immediately switched to para-synthetic oil (blend) and nothing bad ever happened. I sold that truck with 114K to a local guy and he has it up to 167K and still doesn't use any,leak any oil between changes.And he pounds the hell out of it too.

My new truck with a 6.0 liter has run full synthetic (mobil 1) since it was new and I'm at 40K miles now. I change the oil every 5-6K miles because synthetic doesn't need changed as often as conventional oil does.

My Can am with a fresh 400 is currently running Rotella 15-40 diesel oil for 500 miles of break in because my builder wouldn't stand behind the engine if I used synthetic right out of the gate. He couldn't give me a reason, but why temp fate I thought. I've read allot about this Rotella stuff and lots of builders(and guys who know more than me) use it as it has the highest zinc levels of conventional oils on the market. Apparently zinc is something that has slowly been removed from oils and older engines require higher levels and also aftermarket cams seem to have a high early failure rate using low zinc oils.So a fresh engine should run something with high zinc levels to keep the cam from wiping out a lobe early.

As soon as I get a couple thousand miles on the 400 I'll be switching to Mobil 1, as I'm a firm believer in fully synthetic oil.

bobdole369

15W-40 Rotella T here. 2.8L 89 with 235k. Delco filter now, but I used the Fram PH3980 for a long time. I automatically noticed a more responsive oil pressure gauge with the delco filter. Not sure what to make of it, but it seems like it does its job.

I've used everything from Pennzoil 10w-30 to store brand 20w-50, but I'm pretty satisfied with the Rotella now. I live in south FL so I just ignored the 5w-30 recommendation knowing its for a more moderate climate.

gottfuel

intresting stuff guys,.,. i was about 3k miles past do for an oil change i had high psi reading wich i was cool with.,.,then i did my oil change,. i replenisehd her with 5- 30., and now when driving around in this over 100 degree heat and fresh oil it fluxuats alot more at stops it, diped below 40psi,. now im thinking i should do another with 10 -30 and perhaps better brand then the cheap stuff i put in ,..,i used the cheapest crap there is.,now i feel guilty,.last thing i want is fer her to get mad and give me the silent treatment,.,.i cant afford that right now,.this is the most hard of times for me,.,.good oil is good insurance.,,.

sogabe

castrol 20-50 2.5quarts
heavy duty lucas oil stabilizer 2quarts

total 4.5quarts for my engine..

91 3.1L camaro
reaching 190k mile soon with nice and healthy 40+ oilpressure at hot engine.

coolrimsatleast

I switched to synthetic at about 135k, and haven't had any problems since. Currently at 187k.

Maybe I'll have to get some of that high zinc oil for the break-in on my 3.4, which is being rebuilt at the moment before it replaces the 2.8.

W72

iTrader: (9)

Forgive me if linking to another website is taboo here, but here goes...Oil list I posted regarding Zinc ! - PY Online Forums

This is a thread from Performance years about zinc in oils, it's an interesting read and there seems to be some knowledgeable folks over there.