i've been running b20 since oct. now that the temps are in the teens at night? what about gelling with b20?

its in a heated garage at night (55deg).

whats safe?

I have driven B20 in my Chevy and International without any problems for two years now. On the other hand, I am 40 miles south of MI right off I69. I think it depends on your local climate.

In extreme cold down here I have changed to B2, just to be careful. But, that is below 10. When it jumps back above 15, I load it full of B20 again. Good luck.

There isn't one easy answer. B20 raises the cloud point of #2 diesel between 15-25F. So, if your region uses winterized #2 to make the B20 it will cloud at about 20F higher than the pure winterized #2. If your region's fuel is winterized to -10F you should be ok down to about 10F with B20. Note also that the cloud point is not the gel point (also known as pour point), which is about 20F lower. Some engines run fine on fuel below its cloud point.

Of course it is also possible (likely?) that the distributors in your area add extra #1 diesel to the B20 to lower its cloud point further, so there is no easy way to know if your B20 is ok to run even at 0F. I would suspect that any fuel you get out of a commercial pump will be blended for your climate whether it is #2 or B20. Call your station's fuel distributor - they will know.

My area frequently gets into the 20's (as daily lows, not daily average) and I use B80 all winter. If it gets into the teens I will probably add a few gallons of #2.

A good test is to put a small amount of your B20 in a glass jar and leave it outside. When it starts getting cloudy that is your fuel's cloud point. Take a new sample every fill-up because the blends change all winter. Your truck's fuel will probably be ok even when the jar starts to cloud because there is a lot of fuel in your tank and it will retain residual heat from the day. Just use the jar as an early warning. For a faster test put it in your 0F freezer. If it doesn't cloud then you are good to go down to at least 0F.

And Instarx comes in with great info again. That is a great explaination.