CF vs. CF-4

[Robber]

Through a very reliable source I have learned that you should use an API rating of CF over CF-4. However, my source also stated, UNOFFICIALLY, that there is absolutely no difference between an API rating of CF and CF-4. So, what good are all of our theories on API ratings now?

 

[mickey]

They aren't theories, they're facts. Check out API's web site. If they don't know what their own ratings mean, I give up. CF and CF-4 are intended for totally different applications. CF is for high-sulphur, non-turbo engines. CF-4 is for low-sulphur, emission-controlled turbocharged engines. (Sounds like a TDI to me.) CF-4 can be used in place of CF, but not vice-versa. CF-4 oil contains soot dispersing agents in sufficient quantity to handle the high soot levels found in diesel engines which have an EGR valve. CF-4 was superceded in 1994 by CG-4, and most recently by CH-4. The CF rating is still the most up-to-date for it's particular application.

-mickey

 

[Robber]

If a difference between CF and CF-4 is none existant acording to the engineer at the american petroleum institute. Then I think that they needed a new rating for the low-sulphur, emission-controlled turbocharged engines and used the CF standards, but rewrote the procedure to apply to our type of engines and callled it CF-4. That way people would not question the validity of using CF in turbo charged engines. Anyway, I am still looking for some answers. Maybe I should just fork some money and get the procedures to see exactly what the differences are. That is the only way we will ever get the correct answer.

 

[mickey]

The question shouldn't be "Are CF and CF-4 the same?" That's just idle curiosity. The relavent question should be "Are CF and CH-4 the same?" CH-4 is the most current turbo diesel rating. CF-4 was superceded years ago.

-mickey

 

[sljkr]

This one is basic. Check out the chart on API's website at:

http://www.api.org/programs_services/quality/oilchart.htm

As was correctly pointed out, the CF specifically states for "indirect-injected" diesels while the CF-4(now superseded by CG-4 or CH-4) is designed for the turbocharged models.

Also, neither the CF-4 or the CG-4 oils are formulated to meet specs for engines with 1998 emission standards. CH-4 is the only one up to that task, and it is also acceptable for use in previous model engines.

The API does a great job of making it so simple that anyone except a VWoA employee could understand it.


------------------
99 Silver NB TDI

 

[BKmetz]

Hello TDI Nuts,

More oil confusion!

If an API lube engineer is telling you that there is no difference between CF and CF-4, I want to know what company he works for so I CAN AVOID THAT BRAND OF OIL!

I quote my API Motor Oil guide, 8th edition, published 1996, API publication 1551, order number F15518, page 50.

CF-4: Current. Introduced in 1990. For high-speed, four-stroke, naturally aspirated and turbocharged engines. Can be used in place of CE oils.

CF: Current. Introduced in 1994. For off-road, indirect-injected and other diesel engines including those using fuel with over 0.5% weight sulfur. Can be used in place of CD oils.

CF-2: Current. Introduced in 1994. For severe duty, two-stroke cycle engines. Can be used in place of CD-II oils.

CG-4: Current. Introduced in 1995. For severe duty, four-stroke cycle engines using fuel with less than 0.5% weight sulfur. Can be used in place of CD, CE, and CF-4 oils.

My book is obviously to old to have CH-4 listed in it.

But as Micky states, whether or not CF is the same as CF-4 is a nonissue because all oil sold today is CH-4. Any oil that only carries the CF-4 or CG-4 is old inventory. In another year or so there will be a new CI-4 rating! With the new ultra-low sulfur diesel fuel being mandated soon, motor oil for diesels will go through another big change.

And remember, in Europe the API oil ratings don't mean much. Over there they go by the new ACEA oil ratings where there is a third catagory for small passenger car diesels. All gasoline engines use the A ratings, small diesels use the B ratings, and large diesels use E ratings. The ACEA E ratings are close to API C ratings.

The TDI type diesels use B4-98 which is a new catagory for small high-speed direct-injected diesels that have to meet emission standards. The older IDI diesels over there fall under B1-98, B2-98, and B3-98.

[In 2001 VW came out with a new diesel oil specification called VW506.00 to reflect the new ACEA B4-98 standard for TDI type diesel engines.]

Brian Kmetz, 97 Passat TDI


[This message has been edited by Moderator (edited March 02, 2001).]

 

[mickey]

Damn straight, BKmetz! Arguing about the API's own definitions is like YOU asking ME what my name is, then aguing that I'm wrong when I answer you. The API service ratings are exactly what the API says they are, by definition! If they say the requirements for meeting the CF rating are not the same as the requirements for CF-4, then they are not the same. Period. That doesn't mean that a CF rated oil won't necessarily meet the requirements for CF-4, or vice versa, but if someone tells you a particular brand of oil meets CF-4 and it only says CF on the bottle you just have to take their word for it. And why would you want to? There are too many REAL heavy duty diesel oils available to fool around with this tired old arguement. I don't care what Castrol or VW says: If it's just CF and not CF-4, it's not made for a TDI. In fact, it'd better be at least CG-4 rated! ARRRRRRGH!!!!!!! THE END!!!!!!

-mickey

 

[mickey]

My '99 NB Bentley manual says I should use CD rated oil! Even VW is smarter than that! My owner's manual says I should use an oil rated at least CG-4/SJ. The only thing I can suggest that is guranteed to work is to do your own research, and use your own common sense. Your little bitty TDI is putting the motor oil through a much more torturous test than a big, giant commercial diesel loping along at low rpms with 5 or 10 gallons of oil in the pan! Buy the best you can find! I promise you that nobody cares more about your engine than you do. Not VW, not Castrol, not Bentley, not NOBODY!

-mickey

[This message has been edited by mickey (edited June 20, 1999).]

 

[Switca]

What oil viscosity and ratings were specified in pre'99 TDI's?

 

[ecraman]

98 Jetta TDI manual has CD rated oil at all viscosities including 5-30, 5-40, 5-50, 15-40, maybe more. Temperature ranges vary depnding on energy conserving or non. 15W40 is recommended from 0F to 100F. Energy-conserving oils had a slightly broader range.

 

[BRUSSELS BELGIAN]

I hate to agree with mickey, but a Mobil PR person strongly recommended that I get off regular Mobil 1 and onto Mobil Delvac, which has the "-4" rating. He believes that on a car such as the TDI, the "C" rated oils without the "-4" rating are not adequate. Well, if you followed my previous advice, don't get mad: that "bang" you heard was MY engine going to its' eternal reward. Besides, I'm now a complete hypocrite- I even vent my tank!

 

[greentdi]

whatever you do, just don't trust the dealer to put in the right type of oil!! I just had my 5k change at the dealer and they tried to put in Valvoline synthetic rated with a rating of CF! Even valvoline will tell you that is a completely inappropriate oil for our application!! Bring your oil with you to the dealer!!

I feel bad for other people who arent aware of this issue- I know i wouldn't have been aware without this website, but you have to figure that we are not the majority of tdi purchasers--what will happen down the line after all those people who have bought the car and had the car maintained at the dealer experience problems down the road associated with inadequate oil protection? major mistake for vw...