Quote:
Originally Posted by WillSmithTheIII
I work at a Chevron refinery and can tell you that all the teir 1 gas stations are giving you the exact same gas. All the refineries send their gasoline to a terminal where it is blended in large tanks based on their Octane specs. Then when a gas station orders fuel, the delivery trucks are filled up with the gasoline mix and any detergents are added based on the delivery location (I.e. Techron for Chevron stations, NiTRO+ for Shell, etc.)
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What do you do at the refinery?
Certainly the additive package of the gasoline is important. (As an aside this is also what I gather regarding engine oils.)
I have already mentioned of experiencing the benefit of Chevron Supreme w/Techron in my Boxster's engine after switching from Shell V-Power to Chevron Supreme.
But my 996 Turbo engine which was switched from Shell V-Power to Chevron Supreme at the same time -- and both cars received identical usage as I alternated cars for my daily 60 mile work commute -- didn't manifest any signs of improvement. This suggests the Turbo engine didn't develop engine deposits. The Turbo engine was fitted with wide band O2 sensors -- the Boxster engine came with narrow band O2 sensors -- and wide band O2 sensors allow for more precise fueling. Maybe that is the difference. Oh and the Boxster engine had 100K+ *more* miles on it than the Turbo engine. So there are two differences that could explain why Techron helped the Boxster engine but not the Turbo engine.
Our BMW engines are fitted with wide band O2 sensors and have the added benefit of advances in engine control from the 20+ years between the engines in my 2002 Boxster and 2003 Turbo.
But these newer BMW engines are also direct injection and thus no port injection and corresponding fuel spray to keep intake valves deposits (on the back side of the valves) at bay.
My info is that Techron can address these deposits -- in its vapor form -- Techron doesn't burn -- by the post combustion exhaust gas flow which exposes the back of the intake valves to combustion gases. The Techron reverts to its liquid phase upon contact with the cooler intake valves and this works to remove deposits.
Which might explain why last oil/filter service of my 230xi Techron was added to the fuel tank as per BMW when I had the oil/filter service done at 1800 miles.
However, my M2 has had oil/filter services at ~600 miles, 1200 miles (RIS), 4800 miles, and 7196 miles (CBS). I reviewed all invoices and there was no Techron additive used.
I will finish this by mentioning that in my leaving CA for AR and my subsequent switch from having conveniently located Chevron/Shell/Phillips/Unocal 76 stations and offering gasoline at competitive (California competitive...) prices to using discount gasoline none of my vehicles have manifested any signs the discount gasoline is in any way inferior to the name brand gasoline.
'course, I have not put that many miles on my cars. (The Boxster I put 317K miles on it and I put 150K on the Turbo.)
Here the 2020 M-B cargo van accumulated 20K miles (and the engine was as strong as ever when I traded the van in) but my Scat Pack, 2 MINIs, 230i, all racked up under 8K miles.
My 230xi has around 3500-3600 miles and my M2 has around 7500 miles. And I have no plans to replace these cars any time soon.
So as the 230xi and M2 accumulate more miles I'll certainly be on the lookout for any signs the discount gasoline is in any way having a negative effect on these engines.