[gryffishhawk571]

Originally Posted by Adamr916

Man I wish we could get the diesel over here that you guys get. I've found a place here that sells synthetic diesel with a 50 cetane rating compared to the 40 we get at the pump, but I can't justify spending $65 on 5 gallons of fuel

what's synthetic diesel? is it biodiesel? my fuel cap says NO biodiesel

[andreigbs]

If any of you guys have a Cenex fuel station nearby, check out their premium diesel.

Very good stuff.

Otherwise, I suggest a fuel additive like Stanadyne, Hot Shot Diesel Secret, OptiLube XPD, or Amsoil all-in-one diesel treat.

[King Bowser]

Interesting read, makes me a little nervous picking up my 328d haha

[capt_slow]

Originally Posted by gryffishhawk571

what's synthetic diesel? is it biodiesel? my fuel cap says NO biodiesel

He probably meant renewable diesel or biomass-based diesel. Here in CA, we have a vendor that specializes in renewable fuels and their biomass diesel product is called Diesel HPR

https://propelfuels.com/our_fuels

Most renewable diesel fuels are ASTM D975 compliant, which make them safe for use in our cars. They are also given a cetane and lubricity cocktail since biomass diesel has less energy content than normal diesel. I've also seen some stations blend it with real biodiesel in 5-20% quantities.

[FaRKle!]

Originally Posted by capt_slow

They are also given a cetane and lubricity cocktail since biomass diesel has less energy content than normal diesel. I've also seen some stations blend it with real biodiesel in 5-20% quantities.

The low/subsidized price of HPR makes it appealing, however if you factor in the cost per mile (since fuel economy drops) it's actually more expensive than regular diesel still.

I used HPR exclusively for a period of time to test this, and backed up my conclusions with standard statistical practices (such as t-test with 95% confidence interval agreeing that the HPR fuel economy was different than regular diesel fuel economy).

[capt_slow]

Originally Posted by FaRKle!

The low/subsidized price of HPR makes it appealing, however if you factor in the cost per mile (since fuel economy drops) it's actually more expensive than regular diesel still.

I used HPR exclusively for a period of time to test this, and backed up my conclusions with standard statistical practices (such as t-test with 95% confidence interval agreeing that the HPR fuel economy was different than regular diesel fuel economy).

Interesting point, as I also stopped using HPR after about a year and went with the Costco near my house. I just looked at my fueling app and noticed this:
Treated Diesel: 34.15 MPG, $0.106/mi, 35122 miles driven
Untreated Diesel HPR: 33.39 MPG, $0.102/mi, 14972 miles driven

This doesnt take into account changes in driving habits, additives, and etc. Very unscientific.