How many LSPI failures have you seen, or even just read about? There’s probably 1,500,000 posts worrying about LSPI for every engine that’s failed because of it.
Why 93 Octane in a GDI engine if it isn’t called for?
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I agree to your point, but that was not the question at hand.
It is less of a problem now, but oil has changed a bit since then as I understand it. I have seen a couple of 5.3 GMs with a destroyed piston, before the moniker "LSPI" was common. 5.3 DI engines I think one was 2011, and the other 2017.
Have you seen any?, great question.
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I think I’ve heard of 2, maybe 3 total. In 10-15 years. With millions of engines/vehicles. Lol
Nope, while I haven’t scoured the ‘net other than here, I haven’t come across any. That’s partly why I asked and why I’ve said in the past that LSPI is more boogeyman than tax collector (one is a myth, the other is guaranteed) and it may be an issue on TGDIs with manual transmissions, it is easily avoidable with electronic wastegate tuning; simply avoid allowing the engine to make significant boost in low-rpm, high gear, high load situations.
Whether it was accurate or not there has been tests that GTIs and Golf Rs see less valve deposits than other EA888 powered VWs and that was attributed to the cars being driven harder. Maybe turn up the boost and blow the valves clean!
Mine were pretty good at 73K...and I drive it hard.Whether it was accurate or not there has been tests that GTIs and Golf Rs see less valve deposits than other EA888 powered VWs and that was attributed to the cars being driven harder. Maybe turn up the boost and blow the valves clean!
I haven't had mine looked at yet. I'm at 55k miles. I haven't had a reason to. No idle or fuel economy issues before or after the stage 1 tune.
I had my water pump replaced and had them do it.
Copy & paste from Shell:
What makes Shell V-Power NiTRO+ Premium Gasoline different than other Shell grades?
Shell V-Power NiTRO+ contains the highest concentration of the Shell Nitrogen Enriched Cleaning System and
"cleans up faster than Shell regular." In fact, Shell V-Power now contains seven times the amount of cleaning agents required by federal standards. The new Shell V-Power NiTRO+ formulation contains an innovative combination of two key cleaning agents that work together in harmony to provide the BEST TOTAL engine protection you can get. It provides unbeatable protection against gunk and corrosion, and superior protection against wea
right...Shell regular gasoline meets or exceeds Top Tier standards but Shell V-Power Nitro Premium exceeds their regular unleaded gasoline...what is hard to understand about that???
I wouldn't use Premium unleaded fuel if my car wasn't designed (or changed) to take advantage of it...car computers do not "detect" higher octane and tune for that...if your car doesn't need it (higher octane), your car won't take advantage of it to use it...
Bill
I wouldn't use Premium unleaded fuel if my car wasn't designed (or changed) to take advantage of it...car computers do not "detect" higher octane and tune for that...if your car doesn't need it (higher octane), your car won't take advantage of it to use it...
Bill
Back to OP original question:
From my understanding (which is often flawed, at best):
Running 93 does not help prevent intake valve deposits, but it does help reduce fuel dilution in the oil.
I'm a little foggy on the reason: If lower octane fuel is used, the system pumps more fuel in to cool the combustion chamber, depending on load, etc. Like I said, I am butchering that I'm sure, but that information is quite well documented on Honda forums regarding the 1.5T motor.
As for preventing intake valve deposits, seems like the only "help" is running a high quality oil and perhaps installing a catch can; neither of which will likely prevent it from occurring altogether.
From my understanding (which is often flawed, at best):
Running 93 does not help prevent intake valve deposits, but it does help reduce fuel dilution in the oil.
I'm a little foggy on the reason: If lower octane fuel is used, the system pumps more fuel in to cool the combustion chamber, depending on load, etc. Like I said, I am butchering that I'm sure, but that information is quite well documented on Honda forums regarding the 1.5T motor.
As for preventing intake valve deposits, seems like the only "help" is running a high quality oil and perhaps installing a catch can; neither of which will likely prevent it from occurring altogether.
There were a lot of LSPI-related engine failures on Subarus in the early days of their turbo GDI engines. They affected CVTs as well as manuals. This was before SN+ oils were available.
Subaru issued a recall for the Forester XT and WRX to reflash the ECU. I haven't heard much about LSPI problems since. I'm not sure what they changed with the tune, but I don't think wastegate tuning helps all that much, since LSPI can occur at lower boost levels than the 7 psi wastegate pressure, and even the reflashed cars can still make a lot of boost at low rpm.
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Assuming you have Chevron gas stations around you
Is there anywhere documented that it was an oil-related issue?? I went back to a thread from 2016, @gathermewool had posted about his reflash experience… and the cats lighting off faster and less boost on tip in sure sounds like fueling timing & boost issues more than it sounds like oil issues. Even I admit Subaru has not had the best luck with turbos, and that goes waaaay back before direct injection.
Subaru never changed oil recommendations on the cars that were reflashed, and never back-dated requiring SN+/SP when it was available, which, in the absence of proof that Subaru blamed it on oil specifically, doesn’t confirm it was LSPI. You would have thought there would have been huge lawsuits against the oil manufacturers if that was the case?
Plenty a tuner has scorched a piston and/or broken ring lands with power adders, both before and since TGDI was on the scene.
Octane is just rating for resistance to preignition in high compression engines. If you don't need it you're just wasting money and most cars don't need it. As far as cleaning valves it will do nothing in a GDI as the fuel does not contact the valve stem as in conventional EFI systems.
I just mentioned oil standards since the advent of SN+ oils could be an additional reason why we don't hear about this issue anymore. Even if Subaru didn't change the oil spec, most cars would have started using it when it became the new standard. I'm guessing they felt that reflash did its job, so they didn't feel the need to change the spec.
True
The sooner the burn starts, the more complete it's likely to be before the vales open. I don't think it matters either, but it might.
