"Spark plugs are usually never an issue when using RaceChip."
This is still true. We sold more than 500,000 products for 3,000 different car models in the last 10 years. This is the first time that we see a manufacturer having serious quality issues with their spark plugs. This is quite astonishing, because Kia is building great cars nowadays.
One of our customers using 91 octane fuel had issues with his spark plugs. Compared to the quantity of products we sold for the Kia Stinger, this is a very low fraction. However, we want to be always safe, and not just 98% safe. Thus, we want to proactively communicate the safest options for your Kia.
Furthermore, we talked to engineers in South Korea (we have an office in Shanghai and a strong network in South Korea). Kia really seems to have some issues with their spark plugs in combination with bad fuel quality.
Following, we are recommending for a long time now:
NOTICE: The setting "Race" (or mapping 6 or 7) is designed for octane 93-98. Do not use it with 91 octane.
NOTICE: The minimum octane level for using a RaceChip in the Kia Stinger is 91.
This addition is new:
Kia Stinger stock spark plugs are designed for good fuel quality. If used with bad or medium fuel quality (91 or lower), in rare cases the spark plugs might get damaged no matter whether the car is tuned or not. For optimum performance and security of the spark plugs, it is beneficial to re-gap the spark plugs to 0.024-0.028 (from stock 0.034-0.036). Beyond that, suitable performance aftermarket spark plugs with a gap of 0.024-0.028 will improve performance and security.
[MENTION=444]RaceChip[/MENTION], to be absolutely clear your tune doesn't require aftermarket plugs and just regap stock plugs right?
Is the regap required if you are running 93 or higher octane?
According to present knowledge, regapping the stock plugs helps to prevent the misfire.
According to present knowledge, I have not heard of any issues (with or without chip) with 93 octane with Kia Stinger spark plugs in stock condition.
We have 93 octane here too but it has Ethanol. Does 93 octane gas in Texas have Ethanol? and did you regap your plugs?
The Kia Stinger is not made for E-fuels (e.g. E85), so please don't use it. However, it is true that regular fuel contains a small % Ethanol. That's normal.
[MENTION=444]RaceChip[/MENTION] does re-gap apply to the 2.0t too?
This RaceChip product is not available yet. Thus, I can't make final statements. However, from what I've heard, Kia has some issues there, too.
Interesting: We are currently testing the engine intensively and have seen no issues at all.
Kia was replacing the spark plugs of this customer without any questions, so they are aware of the problems and want to solve it with as little noise as possible.