[CT_335D]

I have been filling up my 2009 335d with diesel that has a cetane rating of 40 because that is all I could find in CT. Now I found a new gas station (Citgo) that sells diesel with a cetane rating of 45.

Just wanted to find out what the difference is between diesel cetane rating 40 versus 45?

Which one is better for my car?

I just had my fuel injectors replaced under warranty at 46k miles and I know have 53k miles on the car. So for the last 6k miles, I have been using diesel with cetane 40.

Would my car run better if I start using diesel with cetane 45?

[GreekboyD]

Yes. Cetane rating of 45 is much more ideal for our Ds.

[135i_vs_]

Most stations are Minimum 40 (could be higher).
You finding a 45 cetane station is as rare as spotting another 335D on the road.

Nice find! Care to share location of station?

BMW recommends 51 cetane.

[CT_335D]

Diesel Fuel with Cetane Rating of 45

Citgo Gas Station
529 Main Street
Cromwell, CT 06416

[CT_335D]

You are right about that. This is the first gas station that I have found with a 45 cetane rating. Unless they stuck a 45 cetane label and are really selling 40 cetane level. If so, that would be misleading the customers.

Also, since I purchased by 335d, I have not seen another one on the road anywhere. They are very rare.

[135i_vs_]

Please take a pic of the pump and post here next time. Curious to see what the label looks like.

It's min 40 cetane as per ASTM fuel Standard. This is why you see "min 40" everywhere. It is not a requirement to sell and produce diesel with higher than 40.

If the US is going to adopt the EU Standard in the future, you will see every pump with a min 50 rating. Waiting for that day...

[F32Fleet]

#1 There is no law stating that the pumps must state a Cetane rating. I don't know if a retailor would be in violation of any laws if their pump said a level which was higher than the min and yet the fuel met the min or was somewhere in between min and advertised.
#2 By law ULSD cannot fall below 40
#3 Cetane levels vary between batches of fuel.

Now...your question: "In short, the higher the cetane number the more easily the fuel will combust in a compression setting (such as a diesel engine). The characteristic diesel "knock" occurs when the first portion of fuel that has been injected into the cylinder suddenly ignites after an initial delay (once ignition occurs, all the remaining fuel burns smoothly as it leaves the injector nozzle). Minimizing this delay results in less unburned fuel in the cylinder at the beginning and less intense knock. Therefore higher-cetane fuel usually causes an engine to run more smoothly and quietly. This does not necessarily translate into greater efficiency, although it may in certain engines."

http://en.wikipedia.org/wiki/Cetane_number

[CT_335D]

Here is the picture:

[Sweattdogg]

I pulled off a truckstop once on my way to Wisconsin and they had 2 grades of diesel reg and super. I had never seen it nor ever seen it again. I would assume that that has a higher cetane level as well?

[135i_vs_]

Looking at the pic; is this an old station? I'm not sure if that's the old label still on the pump...the latest cetane stickers look like this: http://www.gasolineadvertising.com/p..._OCRatingA.php

Could be too good to be true. I would call Citgo and verify.

[135i_vs_]

Well how did the car drive on this "45 cetane"? Feel any difference than before?

[CT_335D]

Just filled up the first time yesterday. I had about 1/4 of a tank left with cetane 40 and yesterday I filled up with cetane 45.

I will call the owners of the citgo station tomorrow to find out exaclty what cetane rating is their diesel.

I will fill up there next week with a full tank and see if it makes a difference.

[CT_335D]

Called up the owners of the Citgo gas station to confirm that the diesel is cetane 45. Here is what they wrote back to me:

"Thank you for your call and photo bringing this Cetane rating panel to our
attention. I believe this Cetane rating panel to be erroneously installed on our
dispenser and we are scheduling it to be removed.

As I stated when we spoke yesterday; the minimal Cetane rating for diesel by
law is 40. Product in our tank is at least 40 Cetane; but could be higher.
Cetane content fluctuates according to where the product is lifted and time
of year. During winter months; Cetane is normally higher due to the gelling
of the product with colder weather.

It is not stipulated that the Cetane rating must be posted on the diesel
dispenser; but I assure you that our Motor Fuel Quality Registration with
the State of Connecticut Department of Consumer Protection does specify that our diesel product carries a Cetane 40 rating.

I apologize for any confusion this may have caused and thank you again for bringing this to our attention. We appreciate and value our customer's
concerns.

Sincerely,

Linda"

So it looks like the diesel is cetane 40 and here I thought I found a station with diesel cetane 45. This sucks.

[kbsilver]

You do know that Citgo is a Venezuelan owned company? At least Chavez can no longer be taking those profits.

[135i_vs_]

Originally Posted by CT_335D

Thank you for your call and photo bringing this Cetane rating panel to our
attention. I believe this Cetane rating panel to be erroneously installed on our
dispenser and we are scheduling it to be removed.

I had a feeling...

Don't loose hope yet, I believe US will adapt or have higher cetane rating pumps in 2014, as there is a huge influx of diesels.

[taibanl]

The opposite is often true. Stations may sell higher than 40 but only list 40 bc it's min required by law (example delta sonic)

[135i_vs_]

Originally Posted by taibanl

The opposite is often true. Stations may sell higher than 40 but only list 40 bc it's min required by law (example delta sonic)

I hear some companies"cheap out" and meet only the minimum required by the ASTM, cetane 40. Less addives = more cost savings for them.

Need to figure out the way to read the cetane quality from the car's system; I remember you posted a TSB for this in the past...but special equipment is needed.

[taibanl]

Originally Posted by 135i_vs_

I hear some companies"cheap out" and meet only the minimum required by the ASTM, cetane 40. Less addives = more cost savings for them.

Need to figure out the way to read the cetane quality from the car's system; I remember you posted a TSB for this in the past...but special equipment is needed.

Yes, dealer can read with ista/d

[crazyinp]

Originally Posted by taibanl

Yes, dealer can read with ista/d

Do you have TSB how to do it? I would like to check tonight

[taibanl]

Originally Posted by crazyinp

Do you have TSB how to do it? I would like to check tonight

here ya go:

[crazyinp]

^ thanks! Will try it this week

[taibanl]

Originally Posted by crazyinp

^ thanks! Will try it this week

Let me know, I have never coded but I have the cables so am curious if you can do it this way also.