Engine Oil

[Hawklore]

So, whats the difference between all the engine oils out there??

I need to be able to start the engine up in cold weather, but I need it to stay cool on the highway in the heat of summer here in FL.



Medium to Heavy loads in the bed of the truck, no towing.

75k miles + on the engine allready.

Offroad travel, dusty travel, etc.

[Kev367th]

Should help -

http://www.chevron.ca/ProductsServices/Retail/MotorOilLabel.htm

[eagl]

Good link Kev.

A modern 10w30 oil works for most engines out there.  I'd just look in the back of your car's little owners manual and see what oil is listed in there.  Modern oils are so much better than they used to be, for most cars keeping the oil changed regularly is a lot more important than what exact brand or formula you use.

Oil doesn't have THAT much to do with keeping the engine cool though, unless you have an oil cooler.  Mostly you just need to make sure you use oil that keeps it's viscosity (ability to form a film on bearing surfaces) at the highest temperature you'll run the car at, without the oil being too thick when it's cold.  A modern 10w30 is just fine for use in Florida year round because it's good from below freezing up to around 120F.

If you don't mind the possibility of springing a leak, you could try a synthetic.  They're rated at something like 5w50, meaning they're good from really really cold to really really hot.

My firebird maual recommends 10w30 for most conditions you'll find in the US, and that's what I use year around no matter where I am.  5w30 might make for easier starting, but again you should check the manual.

[Hawklore]

Thanks..

[Viking]

Originally posted by eagl
If you don't mind the possibility of springing a leak, you could try a synthetic.  

Why would it spring a leak?

[eagl]

Synthetics are really slippery and can squirt through some seals.  In a previous car, I had an older engine with about 85k miles on it, and it burned zero oil and only leaked a teeny tiny bit from the valve covers when using regular oil.  I tried synthetic for 2 oil changes and it immediately started burning about a quart every 1500 miles and leaked more from the valve cover gaskets.  I switched back to 10w40 (as recommended in the manual) and it quit leaking and burning oil.

My trans-am has over 120k miles on it including some racing and towing, and it still doesn't burn any oil between oil changes.  I use dead dinosaur 10w30 almost exclusively.  The only *special* thing I do is I try to change the oil every 3,000 miles instead of 5,000 like the manual recommends.

Since I'm moving back to Texas, I might start using 20w50 when racing in the summer, but I might just stick to 10w30 and keep changing the oil at 3k miles since that seems to be working just fine.

YMMV, but if you want to use synthetics you're probably better off starting immediately after you break in the motor when it's still new.

[OOZ662]

Originally posted by eagl
YMMV, but if you want to use synthetics you're probably better off starting immediately after you break in the motor when it's still new.

Read somewhere that you should break in the motor with what kind of oil you plan to use in the first place so that the cylinders bore out correctly for the type of lubricant, or something like that.

[Viking]

Thanks Eagl. I use synthetic oil in the bimmer because of the cold winters we get here, but I have been having small leaks (sweating seals) and it does burn half a liter of oil every year or so. Now I know why, thanks again!

[Captain Virgil Hilts]

Synthetic oils have all of their molecules smaller, and the same size. Most are ester based, and many of them cannot be used with alcohol fuels. Gasohol, 15% or less ethanol  mixed with gasoline is okay, but I'd be wary of high percentages of alcohol, unless you use a synthetic made to run with alcohol. The ester in ester based synthetics is actaully an alcohol ester.

The smaller identically sized molecules is why synthetic oil lubricates well. Imagine two steel plates, with ball bearings in between them. If all of the ball bearings were exactly the same size, and small, you could put a lot more pressure on the plates holding them together and they'd still move, than if you had fewer, larger ball bearings of dissimilar sizes. That's the difference between sythetics and mineral based oils. Mineral oils have larger molecules of dissimilar sizes.

You can successfully switch an engine from mineral to synthetic oil, provided the engine is well maintained, and does not use or leak oil. I switched my Mom's Camry over to synthetic at 95K miles. It now has 200K on it with no leaks or consumption. I switched my Firebird at 12K miles when I bought it. Now at 160K miles of severe beatings, it still doesn't leak or smoke.

I have now moved from Mobil 1 to Royal Purple. Royal Purple is a better oil, and the street oil is not much if any more expensive.

[MrRiplEy[H]]

Here in northern europe all cars are fitted from factory with fully synthetic oils. Service intervals up to 30 000km.

I wouldn't want to try to crank my car up in -30C with 10W-30 oils. At that temperature the mineral oil won't come out of the canister even if you tap it upside down on the bottom. Consequently it can jam up your engine so good that it won't even turn when you try to crank it up without 1-2 hours of block heating.

[OOZ662]

Originally posted by MrRiplEy[H]
I wouldn't want to try to crank my car up in -30C with 10W-30 oils.

I wouldn't wanna live in a place where oil reached that temperature.

[MrRiplEy[H]]

Originally posted by OOZ662
I wouldn't wanna live in a place where oil reached that temperature.

When it gets that cold, trust me, neither do I.

[Maverick]

Originally posted by Hawklore
So, whats the difference between all the engine oils out there??

I need to be able to start the engine up in cold weather, but I need it to stay cool on the highway in the heat of summer here in FL.



Medium to Heavy loads in the bed of the truck, no towing.

75k miles + on the engine allready.

Offroad travel, dusty travel, etc.

Given the age and conditions you will plan to be using your truck I'd not bother with synthetic.

Use 10W30 in the winter and 20/40 in the summer. Your truck is not aircooled so the heat aspect isn't quite as critical as it is in an aircooled engine.

Just change the filter with the oil each time and when using it in extreme dust change the oil at 3k miles. If not in extreme dust change it according to the vehicle manufacturers charts.

I used to use Valvoline in my gas trucks in AZ. during the year. No problems at all.

[DiabloTX]

After getting my LS1 I did alot of research on this question.  It boiled down to what's "right" for the engine as most people have said.  I read alot about the German made Castrol 0w30 and the Mobil1 0w40.  I chose Castrol as that's the brand of oil we used at the MB repair shop I used to manage and I have liked what I've experienced so far, and that is mainly a decrease in valvetrain noise (these LS1's can be noisy) and an increase in oil PSI over the conventional dino oil that was in the car.