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Let's say I already use a GF6/D1G2/SN+ oil and my car is 91 recommended. Will running 93/94 further reduce the chance of a LSPI event occurring?
Does higher octane fuel help prevent LSPI?
- Thread starter OppositeLocK
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I would say yes. Higher octane fights pre-ignition and detonation.
I have to agree with oldhp. Higher octane fuel will give you more benefit than any Dexos approved oils.
It won’t hurt, but don’t count on it helping very much either.
If you have 93 available locally, 91 is probably not going to prevalent. So you are stuck running the 93 anyway with the forced induction engine.
Nick1994
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Yes, it definitely stopped the pinging in my 15’ Sonata.
The classic ping one hears at hard throttle, and which can be addressed with higher octane fuel, isn’t the same as LSPI. It’s more of an HSPI...
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But I'm just wondering if buying 93/94 fuel is worth it if there is additional protection against LSPI. This is on top of using the best oil for it available.
How much difference in cost 91 vs 93? Run a couple of tanks in it, see what it feels like.
Can running an external oil cooler help with LSPI? Does non ethanol fuel improve or prevent LSPI? Gonna run Redline 0w30 in my 2020 CRV
This.
Actually, the modern autos/dual-clutches are brutal for this - they upshift v. quickly and require at times a lot of pedal input to shift down. One has to think that LSPI has been considered by the manufacturers in their shift map logic.
Yes thats true, i have a 2013 BMW and it is just like that, at least in normal "Drive" and comfort mode. I drive it in sport mode to get the transmission to choose a lower gear. Another difference from older automatic transmissions is that its always in lockup and every 8 gear got lockup. My old GM 5L40E got in lockup just on 4th and 5th gear when the speed was over 50 mph, guess the slippage in old transmissions was good in some way
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Yep....I use the paddles and sport mode in my DSG to keep things moving along at times. I have a DSG software tune also that helps with the premature upshifting.
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LSPI isn't your traditional knock event though, I don't think it's as easy to notice.
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Not sure why it's worse with a manual when it's all driver based. Automatics are always tuned for fuel economy and will try to be in the tallest gear possible. Some owners manuals even say some slight knock is acceptable as that's how you're maximizing fuel economy.
That's like saying a BMW M5 is more dangerous than a BMW 3 series because it can go faster quicker.
Lspi is "superknock" that can destroy an engine. I mean the manual transmission is the worst because at some point an automatic transmission will take over control even if you drive it in manual mode if you forget to change to a higher gear when passing the redline to much. At least my 2 Bmw's with automatic transmission does. But i am not sure if it force a lower gear when driving in manual mode to avoid lspi if the rpm is to low and the throttle to high in a high gear so maybee there is no difference but i have never tried that way
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I see what you're saying, a manual is more prone to user error, I would agree with that. But as long as you know what you're doing I think a manual can be safer as you're forcing which RPM to do what at.
For my WRX:
I'll floor first gear at any RPM
Second... floor it only above 2500
Third... floor it only above 4000
Fourth... almost never floor it because its top end speed would result in jail
Fifth/Sixth.... never floor as both are overdrive gears.
That being said, I will still accelerate in any gear but it's very RPM dependent at how I do it. If 6th is on an incline and approaching 2K, I'll downshift to 5th. As long as 5th is above 2.5K, I'll use it to bring up the speed with a third throttle at most.
On the flip side, in some autos I drive I can feel the engine lug going up slight inclines if I'm babying the throttle. I'll have to mash the throttle to get it to downshift but then it'll hunt for the tallest gear again as soon as you get off it.
Manual is safer for LSPI in my mind but it'll come down to the driver.
What do you mean by “worth it?”
If 93 is available in your area, there will be very few stations selling 91, so you’d have to hunt for 91 if you wanted to run it.
In that respect, yes, 93 is worth it. If for no other reason than it’s the easiest supreme grade gasoline to buy, assuming it is sold in your area.
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