I prefer the Wilco for fuel, because they have 45 cetane fuel, where others do not.
That's not necessarily true. WilcoHess does indeed have 45 cetane fuel, but there are others who do, as well.
Most diesel retailers don't make it a point to let you know the cetane of the fuel you are buying (since diesel is a distilled product, not a manufactured product, and can vary from delivery to delivery), but it is important to know what you are getting as best you can, as the cetane number is (one of several measurements) the most significant indicator of the overall fuel quality.
The cetane number is simply a measurement of the ignition quality of diesel fuel during compression ignition. It is a measure of a fuel's ignition delay, or the time period between the start of injection and start of combustion (ignition) of the fuel. The higher the cetane number, the sooner in the compression cycle the fuel will ignite. When the fuel ignites sooner in the cycle, it not only improved cold starts, but will reduce carbon deposits since it will have a more complete burn during the compression cycle.
Pure cetane is an open-chain hydrocarbon alkane molecule, also known as paraffins, which consist solely of carbon and hydrogen atoms, indexed to be 100 cetane. Naptha (alpha-methyl napthalene) is also a hydrocarbon, but with a cetane index in relation to 100 cetane of only 15 cetane. Diesel fuel contains hundreds of components, mostly different types of hydrocarbons, with each having a different cetane level, and it is the cetane average of all of the various components which gives diesel it's overall cetane number. There is actually very little cetane in diesel fuel.
Older engines run perfectly fine on 38 cetane diesel, but most electronic diesel engines require 45 or higher for best performance.
In Europe (and in the US) the minimum cetane used to be 38, as recently as 1999. In 2000 it was raised in Europe (the EU, and Iceland, Norway, Switzerland) to 40, and then a few years later to 51. The rated cetane number is plus or minus 1.
In the US, technically it is a state-by-state thing, not set at the federal level, but most states have adopted ASTM D975 as the standard, which calls for a minimum of 40 cetane, plus or minus 2.
Most diesel to be found at US retailers is in the 42-45 range. The Flying J routinely has their diesel at 40 cetane, and it ranges between 38-41, more often than not. That's one reason they tend to be cheaper than other truck stops around them, 40 cetane is cheaper to produce. If you fuel at the J, you will almost certain want to use Power Service or some other cetane improver.
Fuel at the TA, WilcoHess, Petro, Pilot and several others are usually at 45 cetane minimum, generally in the 44-47 range.
Premium diesel is generally 50-55 cetane, but premium diesel may or may not actually be a higher cetane value, depending on geography and season needs. In cold weather states, premium diesel is often the same 45 cetane, but is treated to prevent gelling, even though it is labeled as premium. In California, CARB regulations require a minimum of 50 cetane. Most diesel in Canada is also 50 cetane, but in Canada it also varies by geographical location and season.
Wilco and TA seem to be the most consistent with their cetane levels, and thus their fuel quality. Petro and Pilot aren't quite as consistent, as their cetane can vary wildly by geographical location (there are still some Pilot locations where they have Low Sulfur Diesel), since they get their diesel from so many different regional suppliers. The Flying J is amazingly consistent at all locations. It's lower cetane, but you can be confident in what you are getting (the one tank of really crappy fuel I got at the Davenport J a few weeks ago notwithstanding).
Once the cetane lever of diesel reaches 55, it hits a plateau, with there being no discernable difference in engine performance beyond that. Some biodiesel, especially that made with animal fats, can be above 60 cetane. Other biodiesel from vegetable oils is generally in the 46-52 range.
If you are unsure of the cetane level of the fuel you are getting, it's best to use a cetane improver. Power Service in the white bottle (Diesel
Fuel Supplement+Cetane Boost) is for anti-gel, but can be used year around, and will add 4 cetane numbers to the fuel. The Power Service in the dingy gray bottle (Diesel
Kleen+Cetane Boost) is for summer use, and will add 6 cetane numbers. There are certainly other cetane-improving additives on the market, but Power Service is the more well known of the bunch. Howes Meaner Cleaner is better at cleaning, and keeping clean, your injectors, but provides no cetane boost whatsoever. I generally use a little Howes in conjunction with Power Service.
Being in a Sprinter, a European vehicle with a European engine designed to run on 50 cetane European diesel, I use a cetane improver in every tank, unless I'm buying fuel in California, or when I buy premium diesel clearly marked as having cetane of at least 50. When I buy 50 cetane at the pump, I'll still use Howes as an injector cleaner and water dispersant, however.
It's like where they have biodiesel, and the sticker on the pump says "Up to 20% biodiesel". Could be 5%, could be 20%, could be anywhere in between. You don't know, and likely neither does the fuel desk clerk. If you drive a Sprinter and you fill up with biodiesel, you'd better add some Howes Meaner Cleaner to the tank to mitigate or eliminate the bio-residue that will be left behind to form carbon deposits on the fuel injectors. This is especially true if you have a later model Sprinter that says "No Biodiesel" on the fuel filler door.
Wait, what were we talking about again? Oh, yeah, the high price of a magazine. I never read the Pilot magazine, so how much they charge for it doesn't really matter to me.
