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jkv357 · 09-30-2011, 03:20 PM

Is there a formula for when gas companies switch from Summer Blend to Winter Blend gas? Is it by temp or by a certain date each year?

Recently (mid to late Sept) I've noticed a significant MPG drop. Temps have been cooler, winds have been pretty high, but it still seems like more than that.

I realize all of the fluids/greases are at a higher viscosity now (mid 50s) than in summer as well, but the car is in the garage so the differences are not huge at this point (60s now, 80s in summer).

Thanks.

Jay

09-30-2011, 03:20 PM	#1 (permalink)
jkv357 Master EcoModder Join Date: Jul 2011 Location: WI Posts: 473 Thanks: 157 Thanked 78 Times in 56 Posts	Winter Blend? Is there a formula for when gas companies switch from Summer Blend to Winter Blend gas? Is it by temp or by a certain date each year? Recently (mid to late Sept) I've noticed a significant MPG drop. Temps have been cooler, winds have been pretty high, but it still seems like more than that. I realize all of the fluids/greases are at a higher viscosity now (mid 50s) than in summer as well, but the car is in the garage so the differences are not huge at this point (60s now, 80s in summer). Thanks. Jay