Originally Posted By: Throt
http://www.consumerreports.org/fuel-econ...emium-gasoline/
True, in most cars. However, they didn't mention nor drive my Solstice or my Jeep. Drive my Jeep when knocking, then run a couple tanks of VPower (Btw, it isn't the octane that is the primary reason I'm running it. It is the higher concentration of detergents), then drive it. Going from knocking to no knocking is a performance increase, in my book.
I'd agree, though, that in most cases, no percieveable benefit exists. I'm still not sure why my Mercedes specifies it, when there is no percieveable benefit in that particular application.
My Ford truck? No advantage to it. Ford Transit? Again, no advantage.
In an engine where timing advance is variable to the octane, and is designed/programmed to take advantage of higher octane, there IS an advantage. In some engines with spark knock issues, there IS an advantage. Another that comes to mind is one of my Dad's old Astro vans with a 4.3 that had a chronic knock. On 93 octane, the knock disappeared. I'd call that a performance advantage, even though it didn't necessarily impact horsepower or fuel economy.
I also agree with them on Top Tier fuel. That's all I run in my vehicles. Guess what, though? The pinging/knocking still develops over time in the 3.8 Jeep, in spite of the Top Tier fuel. I'm convinced it is from deposits caused by oil burning. That's why I'll run the higher detergent V-Power and do a couple Itialian Tune-ups, so that it cleans and burns it out. It seems to work well. I'm on my 4th or 5th tank of 87 after doing this again, and no knock/ping. Mission accomplished, and I don't see it as a waste. The knock/ping is really not bad, though. It just bugs the heck out of me, and I can especially hear it with the doors off.