Grenadier B58 gas engine air filter part #

[Pete Brown]

I have been unable to find a reference for the US B58 gas engine air filter so I popped the hood and removed my original filter and took a picture shown below. I only have 5,000 miles on it, part of it on a dusty gravel section of the Alaska Highway, and it looked nearly new.

1) My OEM is a Mahle LX 3985. (Not an LX 3985/1 or a LX3985/3 ….I don’t however if there is a difference

2) US suppliers Pelican Parts and FCP Euro have them in stock and each also provide a BMW part number which is supposed to be compatible.

 

[Logsplitter]

K&N do an air filter also

 

[MrMike]

K&N do an air filter also View attachment 7858225

After some testing, the K & N filter were found to be the least suitable for off road filtration, from what i can gather they were produced for track work so in short "flow" rather than filtration. Some call them rock stoppers.

 

[TheDocAUS]

The K&N is also known to cause problems on this engine in BMW models, look here.

 

[255/85]

I abandoned oil bath air filters decades ago. I don't think any OEM still recommends or uses an oil bath air filter. Phsyics demands that the media used in an oiled filter must filter out dirt particles just as small as can be filtered out with a dry media filter thus making them just as restrictive. For an oiled filter to flow more air there must be less restriction i.e. bigger holes. You can make your own conclusion here.