Which Weight do you run?

There's no difference other than the 5w flows better at start-up. They both work the same in summer.

 

OP is not racing. Just driving in the cold 6 months out of the year.

10-w40 has been working for him. No problem to keep using it. Unless it is hard to start because oil is cold and thick.

If it starts OK, keep using it.

He says he is driving it longer distances than he has in the past, so that means it has been starting fine in the past. 10-w40 should continue to work for him. The longer he drives per trip will not be affected by the change in oil viscosity.

 

Different valvetrain tech we have flat tappet cams, they have roller lifters and cam.. also i think parts have an anti friction coating..

be my guest, build an engine with no zinc assembly lube on your camshaft and use todays gf-5/dexous SN rated oils.. see how long before your cam lobes go flat
you can still have failures with a roller setup though its not ofen you hear about it.
Main reason the car companies went to ditching ZDDP was for emmisions , too much of it also clogged the cats ..calcium keeps engines really clean and prolongs the life of the cat
1150 ppn with calcium package wont work well like 1200 or 1500ppm with no calcium detergents
say no to API SN oils

why be cheap or ignorant and chance it?

 

back to oil weight, run the thinnest that'll still give you 10 psi per 1000 rpms

 

This suggests that the OEM didn't know what they were doing when they recommended 10W-30. Otherwise, why run a 10W-40 for cold weather driving? Makes no sense.

 

OK I will...

The cam in my Comet is flat tappet Lunati, that's been run on a test stand but has zero miles... I'm going to use off the shelf Rotella 10W-30(same as on test stand), we'll see how it does...

 

While I do use higher zinc racing oils on all my hi-po stuff.. I"ve never run.. and won't on my newest custom ground solid either.. run any fancy additive packages(which in fact has tested/shown to ruin the existing oils additive packaging most of the time anyways).. or fancy "boutique oils". I have run some stuff called "oil extreme" before but gains were very tough to quantify aside from.. maybe.. slightly noticable mileage gains. I was running thinner 0/40 synthetic on both those lower friction roller motors already though.. and it's been said that the law of diminishing returns often applies to those setups.

Also keep in mind that added ZDDP content doesn't(and it's been tested many times) guarantee an oils protective quality will become stronger or better.. but actually just adds to the "stamina rating".. or "TBN"(total base number) so that the oil maintains its protection effectiveness for a longer period of time. It pays to study.

What many don't understand(which is completely understandable with the extreme technical/engineering apsects of such subjects).. is that one oil can have TWICE THE ZDDP of another oil and STILL NOT PROTECT AS WELL. The BASE STOCK.. is THE most important.. and expensive.. and not all oil is the same because of it. Additive packages are the cheapest way to improve on lessor quality base stocks and the rest of the profit margin is made up with advertising and sponserships.

There is a huge thread on Speedtalk about oils and both sides have interesting data and things to say that would teach most of us here a few lessons we haven't learned before.

I'll dig in my HALD("humongous assed link database") to see if I can find them for you guys. Especially the ones who like to read and take things as the gospel truth because some racer said so and sells it to anyone that will follow. Just keep in mind that races and records are set all over the world using many different oils.. so there's always that too.

Personally.. if I'm going to subscribe to advertising theories and pay the resulting price.. I'll take the added benefits of extreme pressure additives like "calcium petroleum sulfonate" over higher zinc concentrations any day. Which is why all the oil companies incorporate it into their "packaging mixs" in the first place. Interesting stuff.

 

Oil Extreme has calcium detergents too their whole selling point is reduced friction ..gain rpms and more horsepower..
I agree with not adding an additive to an oil with its own package..

I thought their were very few "Base Stocks" and was mainly oils with same base but with their detergent packages

Why would you want calcium, its their cause todays cars and emissions systems. Their egr and running engines hotter caused areas to sludge. Calciums' purpose is to remove the sludge..that's it. reason why they diluted zddp, as that was a metal protecting film

The new GDI injection engines ..even calcium isnt a cure which is why they're starting to make a hybrid injection setup..some injectors in head(GDI) and some back into intake I know Toyota is one of them

post that link you talk about, I always love an interesting read and learning

 

I`ll agree w/ Tom about Rotella,I`ve been driving 18 wheelers for over 20 yrs.Get in a truck weighing 80,000 lbs & go west out of Norfolk to Beckly WV on I64 & pull Sandstone mtn.Think about the stress thats put on the mains & rods in the mtr when it takes you 20 mins to go to the top w/ the fan constantly kicking in & out.These mtrs will last(w/ regular oil changes at 12,000 miles)750,000 miles before you drop the pan & roll in new bearings,& the rest of the mtr will last to 1,000,000 miles.I personally like Mobil 1 trk oil a little more than Rotella,but they are both good.It would be hard to argue about the performance of either 1 of these oils,however most guys at the strip seem to like Royal Purple.(just my 2 cents)