yankees1

Just bought a LT1 1972 vette. Has 85,000. miles on engine. Which oil weight should I go with? Thinking about Castrol GTX in 15-40 or 20-50. Only will drive it in spring,summer, and fall and will store it in winter.


[Modified by yankees1, 4:24 AM 8/18/2003]

Tom73

I run 10w30 Mobil 1 in all mine. To me the only reason for a heavy oil is to fill the gaps in the bearings on a worn out engine :(

tom...

Steve Grodin

I've been using 20-50 Castrol oil since the day my engine was rebuilt, per my engine builder, 106,000 miles.

Twin_Turbo

everyone's gotta run what they like but I never use anything like 10W30. There's so much VII in there to keep it from thinning out more than a 30wt (on high temp), and VII don't lubricate. I always ran 10W50 and now 10W60, have tried 5W50 too. No problems at all.


[Modified by Twin_Turbo, 3:42 AM 8/18/2003]

Jvette73

Mobil1 10w/30. Thinner oil will flow at a higher volume. Good protection is about volume not pressure. More volume will keep bearing surfaces cooler.

gliot1

I went through this awhile back. According to all of the major oil manufacturers sites, as well as an independant sites explaining viscosisty, older cars or high mileage cars should opt for 20W50. After researching, I switiched to 20W50, and now have no usage and better pressure. The articles also noted that the additvies used in today's oil are much different in years past, and that the oils today are designed for much tighter tolerances in the engine. Some of the manufacturers actually now make a older car, high mileage oil which is supposed to mock oils of yesteryear. I checked my owners manual (78) and Chevy shop manual which also shows 20w50 reccomended down to 40 degrees. It seems to be working for me. I have a buddy with a '74, and he switched and noticed his consumption drop as well. As long as you follow the manufacturere guidlines, I don't think you can mess up.

Tom73

Don't forget that those manufacture guidelines are based on 30 year old technology. Things have changed over the last 30 or so years and for the better. Check your manuals for the SAE requirements. Bet you cannot find those any longer. They have been superceded by new/better oils.

tom...

Surfer69

Just got back new rebuilt and engine builder also recommends 20w50.

yankees1

Which brand? Thinking about Castrol GTX, Chevron Delo 400, or Pennzoil LL . Any suggestions or other preferences?

fst_c3

Interesting Reading. I went with Mobil 1 15-50 cause thats what Team Penski uses in all there race cars
:steering:

http://www.bobistheoilguy.com/

pws69

My '69 350 Loves Mobil 1 - 15W50...

Corey_68

I purchased a 1990 Chevy single cab stepside truck w/ a 350 and it had 95K miles. It blew a couple puffs of smoke upon start up (valve seals). I switch to Castrol HIGH mileage 25W-50 and run a 1 qt Lucus oil and no more smoke. I put 50K miles on it in the last 1.5 years with no problems. :thumbs: