dale59911

After seeing the thread on oils, etc and all the additives people were using on their diesel, due to the general low grade of #2 diesel in the USA, I did a little research and came up with this from CENEX. I don't think CENEX is just in MT but not sure....I am sure all the Montana CD owners (mmmmmm two? - kind of hard since our UTAH neighbors won't sell us one :-) It was amazing how hard this was to track down....try calling the local gas station and ask them what the cetane rating is on their diesel.....no clue. They could ALL tell me who got eliminated last week on "Dancing with the stars".

FROM THE CENEX WEBSITE

For businesses that run on diesel, a better running diesel.
Announcing newly enhanced Cenex Roadmaster® & Ruby Fieldmaster® Soy-Enhanced Premium Diesel Fuel – containing a special additive to meet the needs of today’s engine technologies!

In engines designed to meet new Environmental Protection Agency emission standards, increased pressure and temperatures can literally “cook” typical #2 diesel fuel, resulting in injector/filter problems, reduced efficiency and costly repairs. We are proud to offer a premium fuel that helps alleviate this problem experienced in modernized diesel engines (2007 models and newer).

Roadmaster® & Ruby Fieldmaster® are also designed to optimize performance and reduce downtime in all diesel engines. In fact, no other diesel fuel contains a more complete, balanced and quality additive package. Compared to typical #2 diesel fuel, Ruby Fieldmaster:

Improves fuel economy by as much as 5 percent
Increases power by up to 4.5 percent
Boosts lubricity by 10-15 percent
Extends life of injectors/injector pumps
Lowers maintenance costs
Has a higher cetane number (typically 48)
Helps prevent fouling issues (in 2007 and newer engines)
Available on the Pump in Missoula Reserve St, Stevensville and Ronan (Fieldmaster only).
Availavle for Bulk Fuel Delivery at all Locations.

grohgreg

48 cetane "premium" is better than nothing, but it would barely be considered a mid-grade in Europe. Caution however. Note the word "soy". That means there's a bio-diesel content, which accounts for the higher cetane rating. Note further that your owner manual is pretty emphatic about using nothing higher than B5 (5% bio content).

//greg//

endless_corners

Yeah the DPF kills the chances for biodiesel. That copy reads like a laundry list of biodiesel benefits. It's just a bunch of marketing fluff though since any high quality biodiesel will have those benefits. If you could delete the DPF and urea injection I bet these engines could handle at least b50. I ran b100 in my tdi for many years.

dale59911

I agree, lots of nuances in the fuels. So many, in fact, that I changed my order yesterday to get the gasoline version. Way too many gotchas for me.

grohgreg

I'm confused. You cancelled a 29 mpg diesel order cuz it doesn't like biodiesel, but replaced it with a 22 (or fewer) mpg order that cant use diesel of any kind

endless_corners

I'm confused too.. Just put pump diesel into the car.. And go. Top off the ad blue every couple thousand miles. The only reason not to get the diesel is to be able to add ptv+ and pdcc or chose a manual tranny. I certainly wouldn't knee jerk about fuels. We are talking finer points of running bio but ulsd pump diesel will run fine in these trucks. At my local pump premium and diesel are the same price.

fincher

Diesel is the way to go. Right, just go to the diesel pump. As for AdBlue, I wait for the warning light and add two gallons. I go about 7-8k before I get the light. Then it's easy to reset the system after adding the DEF. With the 5k oil changes on the Cayenne, you will never have to worry about filling the AdBlue tank.

Only additional thing I do is use the Power Service with every fill up. That's not a 'gotcha' but done by choice.

philg3

How do you reset the warning light after adding the DEF?

hahnmgh63

I believe the Minimum Cetane in Europe is just over 50 with some of the premium Diesel fuels around 60 Cetane. Makes the U.S. kind of pathetic, and part of the reason more manufacturers don't send their high tech Diesels over here. Extra work to dumb them down. Also, our newer low-Sulfur Diesel is still way higher in Sulfur content than Europe. Side note: Most Biofuel Diesels in N. America are an average of 5~7 Cetane points higher than #2 Diesel but the quality can vary from excellent to poor so you may be taking a chance using it from unknown sources.

dale59911

With the price difference in Montana between diesel and premium gas, the cost difference per mile is about .04 per mile (Diesel cheaper than gasoline). The spread has come down a little but it usually runs in the neighborhood of 0.45 per gallon more. Not counting the 5,000 K oil changes and the AdBlue, that gives me a payback of 100,000 miles to recoup the $4,000 USD of the CD over the C with the Triptronic. For the miles we drive, I will be close to 80 before it pays off.

Still have plenty of time to change my mind but the numbers just don't seem to add up.

Love to hear input on the maintenance, reliability, etc of the diesel over the gas. The one thing I do have is a good Porsche independent mechanic here. He raves about the Cayennes he has worked on but, of course, no diesels in this part of the state yet.

Needsdecaf

To me, it's about the torque. Just befits a vehicle of this type. Awesome torque with great fuel economy.

I don't look at it as "more than a V6", I look at it "less than an S".

fincher

Insert key and turn but do not start. Wait at least 30 seconds so system can read the new fluid level.

fincher

The torque is great, the ride smooth. Engine will last a long time. No spark plugs, etc. There is the fun factor, too. If you drive few miles or live in a congested city where most of your driving is short trips with lots of stops/starts, then you will not see all if the benefits.

I live in the Chicago burbs and work near O'Hare so most of my driving is tollways, highways and suburban streets though I'm in downtown Chicago 2-3 days weekly.

gnat

You can't look at recouping the premium for any car that saves gas. The reality is that it takes a lot longer to pay off than sales people want you to think.

The real merits come down to personal needs/wants that are hard to put a price on. In the CD (compared to either the base or S) the items for me were:

1) monster torque. I can't price kicking that torque in and making it move.

2) better mileage. While this has a direct price on it, there is also the lower impact on the environment which is the main factor to me.

3) diesel vs gas. In addition to the burning less aspect on the environment, there is less waste in generating diesel than gas which also equates to a good thing for the environment.

4) option for bio diesel. This isn't practical for me now (no local distributors and no space to mix my own), but I'll do it down the road and this plays more into the environment bit.

5) tuning. Its cheap to get more power out of any turbo engine (my BlueSpark arrived today!!).

6) did I mention all that low end torque yet? (and in a few hours I'll have almost an extra 100 lbs for less than $400! )

dale59911

Thanks for all the input....lots to think about, that's for sure.