I don't know very much about cars...but I am learning. I'll start with that.

Now onto the problem. I just bought a 1992 Dodge Ram Van with a 318. I used to have a 1998 Mazda. My Mazda manual instructed me to use 87 octane gasoline, but my friend told me that I can just disregard that and use 85. When I got my vanI did the same thing. The manual said to use 87 but I have been using 85. I have only a filled the gas tank a handful of times, but I am still worried. I don't hear, see, or smell anything different but I have been reading up on all this, and from what I understand cars now a days have knock sensors that make it possible to use lower octane fuel than the vehicle was designed to use. So the big question is whether the 1992 Dodge Ram Van has those knock sensors or have I just damaged my engine?

Any input would be greatly appreciated!

 

It's unlikely you've caused any damage in such a short amount of time. Just go back to using the 87 and forget about it. Oh and tell your friend that the owner's manual specifies things for a reason.

 

Lower octane gas is sold at higher elevations.

I've not had issues with burning 85 octane bought in El Paso, but 500 miles in any direction from there is still pretty High.

NO knock sensor on a '92

 

I live in Colorado. So I guess that's good.

 

No wait that's really bad! That means that the 85 I used was even lower in octane than most 85s....