Hi everyone,

I’m new here, so apologies in advance if this isn't the correct thread.

I recently bought a 2012 Honda Fit Hybrid (1.3L, Japanese import, GP1 chassis) and am in the process of replacing the spark plugs. The car currently has 8 spark plugs installed.

Car Details:

• Engine #: LDA-5200978
• Chassis #: Starts with GP1
• Industry Model Code: DAA-GP
• Location: New Zealand

The Issue:

I purchased NGK Iridium Double Fine Spark Plug DILFR6J11 from a local auto shop (Repco NZ) as a replacement. However, after removing the old spark plugs, I found they were BKR5E11, which have a shorter thread length.

• DILFR6J11 → 26.5mm thread reach
• BKR5E11 → 19mm thread reach

From my research, it seems that my car should be using the longer thread (26.5mm) DILFR6J11. However, I’m hesitant to install them without being 100% sure, as using the wrong size could cause serious engine damage.

Since I don’t have the owner’s manual and haven’t found a reliable one online for my Japanese import, I’d really appreciate it if someone could confirm:

1. Which spark plug size should I be using?
2. Could the previous spark plugs (BKR5E11) have been the wrong size for my car?

Any advice or confirmation would be greatly appreciated. Thanks in advance!

 

Sounds like someone balked at the $20+ per-plug they used to sell for and installed cheaper plugs.
Wikipedia refers to your engine as LDA-MF6. Fit hybrids sold in other markets used the LDA3 engine. Honda often leaves the last character off JP market engines, I suspect for regulatory reasons. The LDA-MF6 has the same basic specs as the LDA3 - it may be mechanically identical. The North-American Insight (also LDA3) uses DILFR6F11G plugs, which return "not found" on NGK's website - it's a Honda-specific part. That said, the Honda plugs look identical to the DILFR6J11 you bought, though apparently marked as "Dual Iridium" instead of "Laser Iridium".
If you're still worried, install one plug, torque to spec, and turn the crank by hand/wrench a few revolutions. I would tell you to stop if you feel any resistance, but the valves opening and closing causes lumpiness in the rotation. Maybe see what it feels like with no plugs in first? Anyway, remove the plug and inspect - if the electrode is smashed down, those are the wrong plugs.
Even better yet: install one plug, then feed a borescope down the other plug tube so you can record the spark plug get smashed.

 

From what you’ve described, it does sound like the DILFR6J11 is the correct spark plug with the longer thread for your engine. The BKR5E11 with the shorter thread might not be ideal, but if they’ve been in there for a while and the car ran fine, they might’ve just been an acceptable substitute (though not the optimal choice). Since you’re unsure, double checking with a Honda dealer or getting a repair manual specific to your model would be a good idea.

 

Thanks for the information! I am leaning more and more towards the fact that my Fit has the wrong size plugs and that the ones I got from the parts shop are actually the correct ones to install. You’re absolutely right about referring to the correct manual, but I haven't been able to find the right one for my car online. If anyone has a copy I could use, I’d really appreciate it. Thanks a lot, everyone!