Spark Plug Gap

[MKMD]

Hi:

>>>>>>>>>>>>>>>>>1996 LS400>>>>>>>>>>>>>>>>>>>>>>

Ihave 2 questions:

1. What spark plugs. I have Bosch plat plus 4002 Are these Ok?

2. what is the correct sp plug gap?

Happy holidays

M Khan

[killerFatty]

I have heard some shaky things about the bosch plats in LS's. You should stick with Denso or NGK iridium long life. The gap is .044"

[jcrome04]

Denso or NGK Iridium.

And they come pre-gapped so I wouldn't touch it.

[AZ Mike]

OK.....too many similar options here. Looking at sparkplugs.com, it lists the following iridium plugs by NGK and Denso:

Denso Iridium (IK20) $11.99 each

Denso Iridium Long Life (SK20R11) $9.35 each

NGK IX Iridium (BKR6EIX-11) $7.83 each

NGK Laser Iridium Long Life (IFR6T-11) $8.31 each

What are the differences? Is any better than the other for an LS400?

[1990LS400]

It's been years since "high performance" spark plugs made any difference in the way a production engine runs.

IMO, you might as well buy the same relatively inexpensive spark plug type that was installed at the factory when your LS was new.

My 2000 LS400 is due for its first spark plug change at 120,000 miles. It is now at 108,000 miles and still runs like a scalded ape, i.e. perfectly and fast. Spark plugs with some fancy name or design are not going to make it run any better.

If it's like other modern cars, I expect that the original spark plugs will look like new when they come out at 120,000 miles -- and I'll be wondering why it was even necessary to replace them.

[AZ Mike]

All I can say is................bewildering replies.

FWIW, my LS400 came stock with iridium tipped spark plugs, unless my owners manual is lying to me. Earlier in this thread it was mentioned that NGK and Denso are better plugs for this application than others. Based on my experience in other applications, I tend to agree. I looked up what is offered on sparkplugs.com in iridium tipped for the LS400 in NGK and Denso, and the above is what I found. I was surprised to see more than one iridium application by the same manufacturer for my vehicle. I am perfectly happy running my LS400 stock. I am not looking to do anything other than what the Lexus engineers intended. Perhaps the better question would be, "what are the stock iridium plugs in my car?"

Randy & 1990 - Are you suggesting that I should not run the iridium tipped plugs that came stock in my car? I am not seeking a "performance upgrade" or "magic elixir"........just trying to replace what I've got. Sure, I can go spend some time to get the engine cover off in order to pull a plug and check it....but thought maybe I could save that time if someone knows what comes stock on the '99.......

Also, those plugs are in pretty deep. Does anyone ever have the problem of after installing the new plug, and pulling the socket off, that instead the socket comes off the extension and stays on the plug? That happens on my Jeep sometimes, but I can easily reach the socket with needle nose pliers. but the openings for the plugs on my Jeep are not nearly as deep as they are on the Lexus. I have heard of people duct taping the socket to the extension "just in case". Thoughts?

[Zeus253]

Are Autolite Iridium XP good plugs to use instead of NGK or Denso?

[paulo57509]

I would use them.  Just check the gap (but don't attempt to adjust) to confirm they're .043" before installing them.