Summer VS winter octane
#1
![Default](https://www.gmforum.com/images/icons/icon1.gif)
I have a some-what odd question here. In my owner'* manual, it is called for that 87 octane can be ran fine in my engine, but 91 or higher is recommended for best performance. During the summer, I don't notice really any performance difference between running 87 octane, or 93 octane. BUT, in the winter time, I notice a huge difference between running regular and premium. Shouldn't I be noticing a larger difference in the summer, or am I wrong? Does this make any sense?
#3
DINOSAURUS BOOSTUS
![](/images/badges/Gearhead.png)
Expert Gearhead
![Default](https://www.gmforum.com/images/icons/icon1.gif)
Could also have to do with the colder denser air. There'* a lot of factors that change from summer to winter. It'* tough to nail down a single one that is the cause.
#6
Senior Member
Certified Car Nut
![Default](https://www.gmforum.com/images/icons/icon1.gif)
Originally Posted by fantastic88
I don't know what they put in gas for winter but I loose 5 mpg. Actually Custum I would think the 91 would be better in summer with the heat.
Colder air is denser, and requires more fuel then the same throttle position then say a 90* day.
Thread
Thread Starter
Forum
Replies
Last Post