At a car show I went to and participated in over the summer, I won a doorprize, when I went to collect on that doorprize, they handed me a case of Pennzoil SAE 25W50 GT Performance Racing Oil. What exatly does that mean? Is it safe to use? I know that the 25W means that it's thick, but I don't know the other aspects beyond that. Being thick, I don't know if it's safe to use in Inidana, especially know that winter is coming. Thank You for any information that you can lend.

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"Clear your mind, relax, and float downstream."

 

Use it in your tractor or, go to your local dirt track and see if you can give it to some racer for one free admission . That's all it's good for in my opinion

 

The number before the "W" is the thickness rating (viscosity index) of the oil at zero degrees F. The last number is the thickness at 200 degrees F. Typically, an oil is formulated for the "W" number, and then "viscosity index improvers" or VI improvers are added - these are polymers that expand with temperature, taking up the space between the oil molocules thus making the oil "thicker" at higher temperatures. If there is no "W" in the viscosity (for instance, what is called "straight weight" oils, such as straight 40 weight), then it is only rated for the 200 degrees F viscosity.

There are no standards between the two temperatures or outside those two temperatures except for 5W oils, which must have a pour point at or below -20 degrees F. Therefore, this 25W oil could be a solid brick at -20 degrees F, but still meet the 25W rating at 0 degrees F. I wouldn't recommend a 25W oil for winter use in Indiana, that's for sure. Check your owner's manual for more guidance.

The "W" does not stand for "weight", as is commonly misunderstood. It stands for "winter".

Also important is the API rating, which is two letters like "SJ" or "CE". The first letter is the engine type, "S" for "spark ignition" or gasoline engines, "C" for "compression ignition" or diesel engines; the second letter is a series designation (for instance, SF came out in 1980, SG in 1987, etc.). Oils are often dual-rated, with both an "S" and "C" rating.

I can tell you more about oil, but does that give you a starting point? Oh, I'd only follow jcb999's advice if you don't like your tractor or only want to go the the races once.

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82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

[This message has been edited by five7kid (edited October 19, 2000).]

 

I run 20W-50 in my IROC, but my motor is no longer anywhere near stock. Also, I live in Oklahoma. Our normal winters are typically one weekend long at most. You most likely could run this oil just fine in the summertime in a stock car, but it would start getting really thick in the late fall weather. The race track would probably be full of guys who would buy a case of racing oil from you. Personally, though, I'm not a pennzoil guy.

 

IROC,

Was second prize TWO cases of oil?

Oil is for cooking frech fries and mixing with vinegar on salads.

Synthetic lubricant is what you put in your crankcase, transmission, and differential. That is, unless you drive a car with a coffee can stuffed in it's butt or just want a new car every three years.

Mineral oils just don't provide adequate lubrication any more. When engine tolerances were a lot more tolerant, and stresses on engines were generally lower, mineral oil was adequate. Since a better product is available, why would you risk using an inferior one?

Just my lowly opinion.

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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

 

I'll second Vader on this one. I use Mobil 1 synthetic products in both of my vehicles and from the considerable research I have done and the conversations I have had with lubrication engineers I'm certain it is far superior to mineral oil. I've never had any problems with the 1. The only vehicles mineral oil is fit for are rice rockets and fords. Superior machines (e.g. - IROC's, ZR2's, Z71's, Vettes, anything Chevrolet) require superior protection. LOL! Seriously, if you can afford it run synthetic 5W-30 or 10W-30 all year long, especially if you want to keep your vehicle for a long time. Save the 25W-50 for the race track when it's 100 degrees outside or get rid of it.

 

Yea, i agree with jeth and vader.
My car has nearly 200,000 miles on it and it runs like a top except that damn recent stumble and hesitation (not from the oil)

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89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-Future:
-383 Stroker?

 

I used to run Mobil 1 5W30 when I first bought my car. But it's so damn expensive. I've been running either the Quaker State synthetic High Performance blend, or the Pennzoil Synthetic 5W30 blend. This 25W50 stuff was just a door prize they were giving away. How much do you think I could sell the crap for?

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"Clear your mind, relax, and float downstream."

 

I would rather use Mobil 1 and extend the change interval to 6,000 miles to bring the cost in line with regular oil @ 3,000 miles.

I have done this on my engine since new, and it now has 256,000 kms and doesn't burn any noticeable amount of oil. Leak, YES (this will be the 3rd time that I will have the intake manifold off); but burn, NO.

PS: Yes, I have done all the tricks to coating the bolts in teflon tape or liquid teflon also. It just seems to be a cronic problem with my intake manifold where they begin to leak around the 80,000 km mark. I have just resigned to the fact that my car is destined to leak oil through the intake manifold every 80,000 km.

 

I just put Mobil1 25-50 in mine two days ago. I think it'll run just fine.

 

I hope you're either a race car driver or it's about 120F outside! One of the greatest properties of synthetic oil is that it maintains its hot viscosity better than a mineral oil, and therefore you can safely run a lighter weight than normal and still retain good lubrication benefits. 25W-50 mineral oil is one thing, but 25W-50 synthetic is excessively viscous for a street driven car unless you're in a hot climate all year round.

 

I must say I am very confused about this whole oil weight thing. I went to buy some 10W30 Mobil 1 and couldn't find any (I live in New Zealand). All I could find was 0W40 and 5W50. I rang Mobil and asked why they didn't have 10W30. They said they sell different weights in different countries in order to match the climate and driving conditions (New Zealand is generally hilly and we tow trailers a lot). In Australia for example they sell 10W40. We don't have that here. They recommeded 5W50 for my car. They also said that for an old car like mine ('84) the 10W30 suggested by the manufacturer was for the times correct but now days one had more and better choices.

Who to believe, what to do?

The 0W40 Mobil 1 is a bit more expensive than the 5W50. I used 10W30 Castrol Synth in the end.


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Cosmik Debris

 

I don't think their explanation holds water. We have a LOT of hills (and mountains) in British Columbia and we have NO PROBLEM getting 5W30 or 10W30. It also gets quite hot during the summer (up to 40*C) but I have had NO PROBLEM using 5W30 all year round.

I have heard that you really don't want too high of a spread between the first number and the last number (sorry, I don't know the technical terms). This may be more valid for mineral oil than synthetic oil, but they have to add certain chemicals to get the higher protection number from the lower viscosity number. That is why 10W40 is so darn hard to find and NOT recommended anymore.

I'd look a little harder and try and find 5W30 or 10W30. Or phone that dude again and ask him to start stocking 5W30 or 10W30. I prefer 5W30 over 10W30 because the extra protection of the 10W30 really doesn't buy you much and I like the fact that 5W30 shoots to the bearings much quicker when you first start the engine. That is where MOST of your wear occurs on an engine (other than hard driving).

 

It's odd because you can get plenty of 10W40 oil here. On there web page Mobil show which oils are sold in which countries. In Aus they only sell 10W40, here 0W40 and 5W50 as I said, in the states you seem to get 0W30, 5W30, 10W30 and 5W50. It's not like it gets that hot here either. I dunno.


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Cosmik Debris

 

Correct me if I'm wrong, but the main reason we have the lighter weight oil in the states is EPA s--t! The lighter oil makes the engine run more efficiently (less viscous friction losses), and I'm pretty sure this whole thing in the US is driven by the d---ed government. Most new cars nowadays are recommended to run 5W-30 in the US, all the time.

 

Some engines call for 20w50. Find one that does and give it away.

Bry

 

I`m from Poland. There`s every brand and type of oil You want. It`s strange that in Nez Zealand ist the same. Hey maybe I`ll send You some oil ?. I wonder what are the prices in other countries. I ussually buy Mobil 1 5W50 for ~35.5 $ for 5 liters.

-1998 Camaro 5.7 TPI-

 

The "chemicals" are the VI improvers to which I referred in my post above. They do not tend to be shear- or temperature-stable, and are typically the first thing to break down and form sludge, a non-lubricating compound. The higher the spread between the numbers, the more of these VI improver polymers that typically have to be added. GM prohibited the use of 10W40's in their light duty diesels for this very reason (the VI improvers would break down, gum up the roller lifters, and eat up the cam).

While it is true that this is more of a problem for petroleum oils, a certain major oil company came out with their own "me-too" synthetic 5W50 a few years ago. It had more VI improvers than their petroleum oils, and was less stable than typical petroleum oils because of it.

While we need to be careful about blanket statements, it is true that in general, you want to keep the spread between the numbers as low as possible. And, it is also true that nobody currently recommends 50 weight oils (such as 25W50) in their American automotive applications because of fuel mileage concerns. The typical recommendation is 10W30, with 5W30 recommended for below 32 degrees F outside air temp operation.

As for what to do with the stuff you "won", give it to Salvation Army and claim $1.49/qt charity deduction on your income taxes.

 

Hmm. I finally found something that I disagree with Vader on. I think oil is oil. In every car I've owned except for my IROC, I've used the cheapest oil I could find. Usually the $.87 wall mart store brand. I sold my 86 firebird with 145k and it ran like a champ. I sold my cherokee (2.8) with 145k and it ran like a champ. The kid is still using it, and he's a 16 year old that hammers the **** out of it. My 86 camaro has, oddly enough, 145k on it. I hammer the **** out of it. Constantly. I break trans mounts with a 2.8 . Nothing but the cheapest possible oil. Most of the time those cars all go WAY over 3,000 miles between changes too. My 86 just got its first oil change since sometime around January or February.

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