autolite plugs removed!

[brick8]

I am catching up on deferred maintenance on my new-to-me 525it. Yesterday I replaced a pretty dirty air filter. I also yanked the autolite plugs that came with the car (see picture) and replaced them with stock bosch plugs. What do you think of the old plugs? I don't think I have ever seen rusty spark plugs before in a car. The funny thing is the car seemed to be running OK with these plugs and the dirty air filter.

[acidfire52]

Picture is a bit fuzzy... hard to see.

Look ok to me though. She should run a little better now.

[BMWCCA1]

Over the years I bought a lot of M50-engined BMWs at auction for our dealership that had Autolites in them. I never found any improvement in mileage or running from changing them to "proper" OE plugs. That being said, i still use the "correct" plugs in my cars. The Autolites got started as a cure for surging in the BMW R1100 motorcycles, and quite successfully. I believe they cost about $2 each so you can see why its so tempting to use them in the cars. Honestly, some of the best running 525i's I've driven were later found to be packing Autolite plugs. What can I say? Those were blind tests using a well-calibrated butt dyno...

[brick8]

Just got back from a 100 mile drive. You are correct, I cannot tell any difference. My guess is that the engine computer must compensate for whatever minor difference there is in spark.

[gtopaul]

I've been running Autolites in my Bimmers for years without problems. Seems strange in the twin electrode M50 that the single electrode Autolite plug works just fine. If Autolite has a listing for it I'll use it. Left over thought pattern from my old drag racings days. Never fouled an Autolite plug.

Paul