What Fuel Additive do You Use?
03-15-2019, 11:51 AM
#16
I use regular unleaded as well with the anti knock sensors, no problem. If I want a bit more power for the mountains or spirited driving then I use premium. No need for a fuel additive.
03-15-2019, 12:08 PM
#17
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Prolonged use of a fuel additive (an additive YOU add, not the stuff that comes with your fuel fill-up) decreases your oil's flash-point. A decresed FP is a lower viscosity oil. Not a good thing. A keen eye, will see this on a UOA. That's one of the reasons you want to use about 300-400 miles BEFORE your oil change.
03-15-2019, 12:13 PM
#18
In a base or an S, that might be OK, but not in a turbo or GTS The GTS is tuned differently where you'd like get knock from predestination, which is especially bad on a DFI motor - research LSPI - and on a turbo the boost pressure makes that even more likely is the octane rating isn't high enough to prevent it.
Having been unable to get even 89 octane in a pinch once, my GTS knock sensors work great and the ECU is more than capable of completely turning your fire breathing NA V8 into what feels like a tired 1975 cadillac V8 on a moment's notice.
03-15-2019, 12:32 PM
#19
dr914 is adding to the quiet silent majority vote! 
FWIW you could pull the injectors and have them flowed every 50/100k to see if they are still in spec. There are places that specialize in this service. Usually, I just get mine on an exchange basis when I need a specific injector that is used/unknown. (about $80 a set of 8)
Note: This service is for regular injectors... IDK if DI injectors would be different for servicing.
Just a thought as I am not a fan of adding anything to fuel or oil. If the factory owners manual does not specifically recommend it, then don't do it. Modern cars with recommended service will easily go 200k+.
Any of the mega milers want to chime in on the secrets of longevity?
FWIW you could pull the injectors and have them flowed every 50/100k to see if they are still in spec. There are places that specialize in this service. Usually, I just get mine on an exchange basis when I need a specific injector that is used/unknown. (about $80 a set of 8)
Note: This service is for regular injectors... IDK if DI injectors would be different for servicing.
Just a thought as I am not a fan of adding anything to fuel or oil. If the factory owners manual does not specifically recommend it, then don't do it. Modern cars with recommended service will easily go 200k+.
Any of the mega milers want to chime in on the secrets of longevity?
03-19-2019, 12:43 PM
#21
Rennlist Member
V-power 93 whenever I can, which is almost always. Gonna try a bottle of Techron before this oil change just to see what, if anything, it does.
’06 CTTS 145,000 miles
’06 CTTS 145,000 miles