Sensors malfunction and fail. Keep on being a miser, though. You're the type of guy who runs Motorcraft synthetic blend oil for the full duration of the computer indicated OCI just because it's "ok" to do so. I feel sorry for the people who buy your cars second hand.
Actually I'm the type of guy that puts full bolt-ons and cams in a Ford Escort then tunes the ECU himself with a SCT Pro Race package, had a full bolt-on Lund tuned Mach1 within 6 months of owning it, and never lets a "blend" touch his car after original OCI, but go ahead in your horribly inaccurate assumptions. Probably why you have NO idea how compression, fuel and timing relate.
Actually,
Ahhh see its not just pulling timing, it also able to ADD timing. Please go read up on modern engines and then we'll have this discussion.
IT IS NOT PERFORMING AT PEAK ON 87 OCTANE AT SEA LEVEL, OR EVEN AT ALTITUDE FOR THAT MATTER. What is wrong with you?! Go read up on modern engines?! You have no idea who you're interacting with...
Clearly someone that doesn't understand how engines work. He doesn't need it to work "at peak" he's just driving down the highway barely over idle. He's not flooring it around like a 18yo kid. So he wants to drive to Florida, and lives in Maine. Using 87 vs 93 down and back will save him about $40, that's basically a free tank of gas. Why should he NOT do that if he wants to. Hes not dyno-ing the car, or drag racing it, hes rolling at 1200RPM on the highway. Do you not understand "use case"?
For 2015-17, AAA tested regular vs premium.
Oh yeah, totally. I have no idea how they work. I'm so glad people like YOU are around to educate ME.
Like I said, not peak.
Look, if the sensors are defective to the point that it's pinging at idle with 87 octane, that's enough to go have it fixed at the dealer. If it's adding so much timing that it pings at 87 octane, the sensors or variable timing is clearly messed up. He doesn't need to put 93 in it to see if it still pings because it shouldn't be pinging in the first place. What's next, race gas? Or you want him to run a tank of e85 through it?
I would have suggested he attempted it just to make sure what he was hearing was pre-ignition, or something else. A boost in octane would have changed it, confirming his diagnosis. Then off to the dealer. Is that so hard to understand?
What makes you think it wouldn't ping on 93?
If it were fuel related, it would MOST LIKELY lessen on 93 vs 87. I believe you should troubleshoot to the best of your ability before you pass the car off.
it'd take at least one full tank of gas before 93 even got into the system. Who has time for that? He has a warranty for these sorts of issues. Why should he spend time diagnosing the issue when it's the dealers's job to do that? This isn't some small issue. The engine is at risk if it's pinging at idle.
It wouldn't take very long depending on how full of 87 he is. Everyone should have time for that. HE should troubleshoot to the best of his ability in order to guide the dealership. He hears a "little bit of pinging" at low load in first gear. It's not like he's full on can of nickles mode. Troubleshoot troubleshoot troubleshoot.