Premium Diesel Map

[93celicaconv]

This thread may be very old, but is very pertinent yet today. I also would like to get more information on what fuel stations in my area (Appleton, WI) sell premium diesel (cetane > 46, high lubricity, good additive packages). I know Cenex Roadmaster XL fits the bill, but most Cenex stations don't carry this fuel - found a cooperative that does, but its 15 miles from where I live. There may be other premium fuel sources on my block, but finding them is hard. How does one do that?

 

[Lightflyer1]

By leg work is the only way I know. Even when talking to those involved most have no idea of the specs of their fuel being sold. From my experience from long ago even when contacting the head offices they will only quote you the spec minimum requirement no matter what their actual spec is in reality. Good luck with that!

 

[tdiatlast]

...what he ^^^said.
With that in mind, i am of the opinion that ULSD quality has improved since the early CRTDI (2009) HPFP failures. Someone might post current studies that bear this out...

IF I were currently driving a VW CRTDI, fuel quality would not be high on my list of concerns (while always buying from a high-turnover station, though!)

 

[93celicaconv]

I wonder what would cause diesel fuel quality to improve? Improvements typical come at a cost. Consumers typically look at lowest cost. Individual distributors would loose sales if their diesel fuel cost more, based on consumer reaction. And there are no higher EPA/CARB/ASTM standard changes forcing higher quality. The attached below piques some thought:

The principle measure of diesel fuel quality is its cetane number, a measure of the fuel's ignition quality. Cetane number influences combustion. Requirements depend on engine design, size, nature of speed and load variations and starting and atmospheric conditions. A higher cetane number indicates that the fuel ignites more readily and burns more completely when sprayed into hot compressed air.

In the U.S., the Standard Specification for Diesel Fuel Oils (ASTM D975) establishes a minimum cetane requirement of 40. Most diesel fuel sold in North America has a cetane value between 40-45. Diesel engines operate best on fuel with cetane values of 50 or higher. To protect diesel fuel-injection equipment, ASTM D975 requires diesel fuel to meet a lubricity requirement of a maximum wear scar diameter of 520 microns in the High Frequency Reciprocating Rig Test (ASTM D6079).

This tells me higher cetane numbers has a return value. And the early VW CR-TDI's were designed for a maximum wear scar diameter of 450 microns. I'm not sure what the 2015 EA288 engine HPFPs are designed for regarding wear scar diameter, but the early (2009-2012) EA189 engine HPFPs were designed for higher fuel lubricity values than the US ASTM D975 regulations require.

The Cenex cooperative (where I currently get my Roadmaster diesel fuel from) went to this premium diesel fuel vs. Cenex's normal diesel fuel years ago, at a higher terminal cost, largely because they consume most of the fuel they purchase in their equipment, and the ULSD fuels were costing them downtime and maintenance repairs on their fuel pumps and injectors (so says the owner), and they rationalized the increased cost of the fuel would decrease the cost of their downtime and maintenance repairs (savings would more than offset the additional fuel cost). After a few years, the owner felt the premium fuel exceeded their cost savings goals, so they kept it and also offer it for sale on retail pumps for the general public to purchase. This is what I would call a study that provided at least this cooperative a cost advantage to have a premium diesel fuel. And, given their consumption level is high, so also they tend to have relatively fresh fuel in their pump tanks.

So I think there is cost value in premium diesel fuels, given the history of VW-Bosch HPFP failures (and the cost to repair, and the out-of-service time) and this cooperative example. Hence the reason for my inquiry. I agree with Lightflyer1 - there isn't much credibility in a fuel station attendant regarding giving you accurate information on their fuels - they don't typically know. And if they did, in weeks or months, they may change their source or quality of fuels anyway. No regulations exist to post fuel quality values on the pumps for the fuel in the tanks either. I guess I'll just have to accept the fact that "it is what it is" and move on.

 

[Lightflyer1]

Some states like California require higher cetane values by regulation. The Euro standard is 50 or 51 IIRC. Ours cars run just fine with the cetane we currently have though. IIRC the truckers (as a group) rallied against raising the standard as the fuel would cost more. Lubricity seems to be the more important of the two though as that was what was driving the disintegration of HPFP pumps. Bosch spec'd 400/360 or lower IIRC. 2% biodiesel was shown to provide the needed lubricity better than anything else. So if your fuel has at least 2% bio content, lubricity should be fine. There are always cetane and lubricity additives if you choose to use them yourself. The improvements to the diesel fuel happened when the changeover to ULSD was mandated and after.

Here is the 2016 Infineum Diesel Fuel Survey results FYI:

https://www.fuelsinstitute.org/fuel...rldwide-Winter-Diesel-Fuel-Quality-Survey.pdf

 

[romad]

California's minimum cetane number is 53. CARB Diesel is the only CARB program I agree with 100%

I consider that fuel survey as useless without brand and actual location of the tested fuel source.

 

[Lightflyer1]

It is what it is. Anything better you can point to? Does California meet its cetane requirements? What is the lubricity requirement if any?

 

[Jetta_Pilot]

I see that in the Americas, Mexico is totally absent. Once again there was a rumour that ULSD was to become available at the end of December 2017.

 

[93celicaconv]

California's minimum cetane number is 53. CARB Diesel is the only CARB program I agree with 100%

I consider that fuel survey as useless without brand and actual location of the tested fuel source.

That and the survey only covers winter diesel fuel. Summer grades may be different, as they actually state. I found these pieces of interest in the survey:

Page 15: Lubricity: In North America a worsening picture for average lubricity has been observed in Canada, and in the East and Mid-West regions of the US."

I live in the Midwest.

As I look at pages 24-30, I see average HFRR (lubricity values ranging from 180 (Brazil, and lower is better) to 519 (Saudi Arabia), with many countries below 200 - the US ranges from 328 (East) to 449 (West) - something tells me the east value was recorded wrong and should be 428 as I don't think the US diesel fuels would have this kind of discrepancy across the country. By far more HFRR values in other countries below the US than above (meaning the US is very low on the lubricity quality of the fuel).

On the same pages, the average cetane numbers range from 63 (Finland, and higher being better) to 43 (Canada), with the US in a range of 45 (both East & Midwest) to 54 (West). Most all other countries are in the 50's (meaning the US is very low on the cetane quality, or combustion efficiency, of the fuel).

So by far, from a lubricity and cetane perspective, the US regions have relatively poor quality diesel fuels being sold.

Someone earlier said about truckers lobbying for lower cost diesel fuels to keep US transportation costs down. I think I remember those times when ULSD was becoming a reality. And maybe our transportation infrastructure in the US is a much better value than anywhere else in the world. Or is it? I just keep thinking back to the case where a cooperative compared true costs of lower priced diesel fuels to maintenance and downtime implications, and then switched to higher priced premium diesel fuel which more than offset the fuel cost increase by lower cost maintenance and impacts of downtime.

As Lightlyer1 said, it is what it is.

 

[romad]

It is what it is. Anything better you can point to? Does California meet its cetane requirements? What is the lubricity requirement if any?

Unfortunately, it does drop the ball on lubricity, accepting 520 microns, so I revise my support to 75%.

 

[93celicaconv]

Unfortunately, it does drop the ball on lubricity, accepting 520 microns, so I revise my support to 75%.

Yes - Western US lubricity values are very high (meaning poor lubricity), maybe because the sulfur content of the fuel is considerably below 15 ppm, on average, with no additional lubricity additives being provided. Cleaner air, more wear on metal-to-metal contact surfaces pumping or dispensing diesel fuel on the vehicle.