I have been putting 87 fuel in my truck. The manual says 87 Octane Acceptable. 89 Octane Recommended (which is not available in CO). I live in Colorado with high elevation and our fuel grades are only 85, 87, and 91 octane. Should I be putting 91 octane in my truck since we do not have 89? I am getting about 15-16 mpg city and have not been doing highway yet but I think I will average over 20 mpg.

I am concerned about the 87 fuel because my car sounds like it has a exhaust manifold bolt break or leak. Making that weird ticking sound. I have an appointment this Saturday with the dealership. I believe the prior owner was putting cheap gas in the truck. I have had this vehicle for only 1 month and it has only 83,000 miles on it.

-Jessi

 

What you are hearing is probably pinging or detonation from using low octane fuel. Put some 91 in it and see if it clears it up.

 

I live in Southern Cal at sea level. I ran 87 on my 2009 for 120k miles without any issues. The only time I used 89 was for towing. I have driven in the high altitudes of the Colorado Plateau (Colorado, Utah, New Mexico) and had no problem running 85 octane. In some places, I could only get 87 and used it for towing, never had an issue. As a matter of fact, I got better MPGs driving up in the higher elevation due to thinner air.
You probably have an exhaust leak.

BTW, I now have a 2017 Ram with the hemi and still run 87 octane. No issues whatsoever.

 

Thank you. I think it is a leak as well. We will see.