It out of the two cars I have, both are running synthetic in both, my summer driver, a 305 91 GTA has 5W30 Castrol edge and I put the same oil in my Camaro with a 350 with Edelbrock heads that belongs to my old man. Well he damn near **** his pants when found out I put 5W30 in his engine, told me to find some 20W50, and we had agreed to run synthetic in this engine (we didn't built this engine, and we have never taking it apart), and the highest grade of synthetic I can find is 5W40
What should I do? Run 10W30 or run the 5W40 or spend the big bucks and use Royal Purple (I really don't want too)

 

I found 3 different 20W-50 synthetic oils at Advanced Auto.com



http://shop.advanceautoparts.com/web...dditives_15035

What year is your dads Camaro? Using heavy weight oil isn't as important with the newer cars as it used to be because tolerances with newer engines are much tighter.

 

He wants you to use racing oil? Hes probably been watching too much NASCAR...

 

The Camaro is a 81 but the block is from a 90 truck, we didn't built the engine, it came out of a wreaked TR6, we just figured to put synthetic in it

 

one thing to keep in mind - if you've been running dino oil (non-synth) in an engine for a long time, and switch to synth, youre GONNA GET leakage - guaranteed cuz synth molecules are much smaller, they will fiind every leakage point.

 

What would happen if you had an engine with only a few 1000 miles on it but it had sat for years and then you switched to synthetic? Oil pan, timing cover, valve cover gaskets and front crank seal have been replaced though.

 

any imperfect seal and the synthetic will find it. if the engine has been sitting for years, i'd bet some of those new gaskets and seals have lost some integrity. Why not just try the synth out? You might find some leaks you can easily fix, maybe not. But you could just go with dino oil and be done with it. in actuality, the temperature handling difference between the two types is not that much. and unless you drive the car at real low ambients, the flow superiority of synth doesnt buy you much either.

 

I really, really suggest you guys listen to this:

http://www.podtrac.com/pts/redirect....t/CC_EP526.mp3

It's pretty interesting. It's Adam Carolla's carcast episode with guest Lake Speed Jr who talks pretty candidly about synthetic oils and zinc oils and so on. It's very informative.

http://www.adamcarolla.com/CarCastBl...-jaguar-xkr-s/

Synthetic oil is more stable at high temperatures and lasts longer at high temperatures. The protection afforded by dino oils starts dropping rapidly at.... I think Lake SPeed Jr said 230F? Maybe 260F? And drops significantly from there. David Vizard in one of his books said that usually the engine oil runs 30F hotter than the coolant. So that will vary depending on load and components and whatnot, but that was the baseline rule of thumb.

Just food for thought.

 

Off the shelf "synthetic" is Dino oil. The myth about leaky seals came from a time when synthetic branded oils were actually made from group v ester base stock, before Mobil sued castrol over false advertising and misleading consumers. Mobil lost.
Anyway that's besides the point, I encourage everyone to do research on the products they use. A real synthetic like redline, royal purple, or amsoil is completely different than Mobil 1 or Penzoil.

As far as 20w-50, O.o, you, uh, live in B.C. They shouldn't even sell that weight where you live especially this time of year. What's it like -40 up there? You should be using 5w-30 max. During the summer you should use 10w-30 with a zinc additive if you have a flat tappet cam. This explains it much better than I can so have a look: http://www.upmpg.com/tech_articles/motoroil_viscosity/

Using 20w-50 your basically dry running the engine for a few seconds at start up and wasting energy pumping that heavy oil at warm up.

Good luck convincing your dad of all that, if he's anything like mine, crap the learned/hear from Joe schmo who had a fast car when they were young > technology and actual facts. :P

 

Ding ding ding ding ding ding ding!!!! We have a WINNNER!!!!

Only took 4 posts for some n00b to trot out the tired old MYTH.

Most of those, I can figure out how they got started (since I've been around since before they have); that one though, eludes me. Must have been an article in a magazine I didn't read. Oh wait .... that would be pretty much EVERY article in EVERY magazine.

Ignore that crap. It's as much a bunch of crap as it was the day some hilljack invented it.

Tell your dad you appreciate his advice; thank him kindly for his concern and willingness to provide input; then IGNORE HIM too and go do what it RIGHT for your car. Which is, exactly what you have already done.

Mobil1 is as much "synthetic" as any of those other oils. Yet ANOTHER myth that just won't die, spread by people who have AGENDA. It was developed BEFORE them. Castrol, Pennzoil, Valvoline, etc. are not; they are re-hashed dino juice.

 

This. Mobil 1 extended performance is a true synthetic made from PAO group IV stock and contain no parrafin. The rest is just fancy marketing.
The leaky engine myth came from early synthetics made from group V ester stock. Ester based oil has poor seal saturation and is not compatible with Dino oil (this is also where not mixing sythetic and Dino comes from). Group IV stuff is compatible and is pretty much what most true synthetics are made from nowadays. Ester stuff is mostly only used in military grade turbine oil and industrial grade air compressors and hvac stuff.