The local paper had an article in the business section concerning gasoline quality that was kind of a reminder for us, but may be new for others.
AAA: Not All Gasoline Created Equal | AAA NewsRoom
We usually try to buy Top Tier gas, which is easy at home because we know what stations have it, but tougher when traveling because of needing to be diligent about knowing what stations are up ahead that are on the Top Tier list. Good reminder for us to print a new list for the van.
When we first heard about Top Tier a few years ago, I checked out what it was, and where it came from. Basically more and better detergents in the gas to prevent deposits in the engines. They often talk about the deposits on the valves and pistons, which is a primary problem, but from what I have heard, deposits on and in the fuel injectors can also be an issue. The program grew out of European findings that certain vehicles where having lots of deposit problems.
I know we will hear from lots of folks who always buy the cheapest gas they can find and have not had an issue (that they know of because you can't see it). We know lots of them ourselves. I also know that from the engines I have had apart, and the tons of junk yard heads I have messed with, how much deposits there are is very, very, variable, and can be substantial. We choose to be on the careful side on this one, and my guess is that if you keep the vehicle for a lot miles you probably come out pretty even on cost because you won't lose as much mileage as the vehicles age.