low cetane diesel fuel cause choppier idle?

[The motor guy]

I've been using either murphy fuel or Kroger fuel the last year or so and occasionally i'll fill up at the shell station that's brand new and has the same price as Kroger and walmart. I noticed whenever I use the shell fuel it runs good, but whenever I use the cheaper fuel I notice a bit more of a lope out of the engine standing by the exhaust. I don't think I've noticed it when using the shell fuel. It runs nice and smooth. What do you guys think? I always use stanadyne lubricity formula, this lubricates, but doesn't increase the cetane any.

 

[Chris142]

Here all the fuel comes from the same supplier. I imagine your area is the same.

 

[CarbonSteel]

I am noticing the same with Kroger fuel versus Shell or Chevron. The engine does not run as smoothly on Kroger and I get 1 to 3 less MPG.

 

[The motor guy]

Originally Posted By: 2015_PSD
I am noticing the same with Kroger fuel versus Shell or Chevron. The engine does not run as smoothly on Kroger and I get 1 to 3 less MPG.


Interesting... sounds like a slight miss and you can feel like in the air flow coming out the exhaust. I know we have [censored] diesel fuel compared to Europe. Supposed to 50-55 cetane rating, but it's not uncommon to have 40-45.

I guess it's a lower cetane rating that would cause it, not sure what else what cause rougher idling.

 

[Jim_Truett]

Are you sure it's pure #2? One of my go-to stations started selling B20 without notice, and the sticker on the pump was small and inconspicuous.

A higher cetane number can definitely cause a smoother idle.

 

[The motor guy]

Originally Posted By: Jim_Truett
Are you sure it's pure #2? One of my go-to stations started selling B20 without notice, and the sticker on the pump was small and inconspicuous.

A higher cetane number can definitely cause a smoother idle.


I know walmart had b20 stickers on their pumps for a while, but then they disappeared. A lot of stations had stickers that said 5-20 percent bio diesel, but now they all just say 5 percent.

 

[ironman_gq]

Most diesel in the states is 40-45 Cetane. Higher Cetane fuel makes for a quieter smoother running engine and often produces more power. Different suppliers will have different Cetane ratings.

Most big box stores like Walmart and Kroeger will use a lower quality fuel to save cost (US law mandates a minimum rating of 40). I did see a chart at one time that Shell branded diesel has a Cetane rating closer to 50 but that could be regional and would assume that your shell station is selling Shell blended fuel. Seasonal blends will also affect Cetane rating.