Gas Mileage and KN

[Kulbiker]

So now my trust steed 325xi E46 is about 2.5 years old and running like a dream with a few minor hiccups...nuthing to write about anyways. Yet the one thing that always troubled me was mileage. I used to eke out like 250 miles max from a full tank of premium for the last two years. Which is mainly city driving by the way.....my highway use is minimal. So I consoled myself saying that its an all wheel drive....city mileage yada yada...18 mpg is not bad. Then few months back I bought a KN Air filter and replaced my engine oil and put in a KN oil filter. Miracle or miracles my gas milage in two months since has jumped to almost 420 miles/tank. WOW! I never thought KN would make that much of a difference. I am now almost upto 24 MPG which is phenomenal considering the latest prices of gold....sorry gas. . This is city driving mind ya....I had half a mind to chastising the editor of CNN money for not putting my bimmer up here. Lol they had a Chevy corvette on it has 5 best milage cars.....:lol: laughed my ass out. Ciao people.

[325isBaby]

Be careful when you re-oil the K&N make sure you don't over oil it, if you do the oil will coat your MAF and kill it...just thought you should be aware

[SpooldUp]

Good to hear the filter saved you some gas. If you drive in the city where the air is dirtier dont forget to clean/oil the filter like every 10000 miles.

The corvette HIGHWAY spec is 28 which gets the award for it. Cruising at like 1400 rpm at 70MPH in 6th is to thank for that.

[Hootie]

Uhm, I've gotta wonder about that credibility. No one goes from 18mpg to 24mpg, all else being equal, because of an air filter change. I have a 2000 328i and I get about 20mpg mixed driving. No matter what changes I've made with oil, tuneups, spark plugs, filters, etc. I've never done better than 22mpg mixed driving.

[Kulbiker]

I was shocked myself that there can be such a change in the mileage byt just an oil change and filter replacement. But beleive me unless my OBC trip calculator has suddenly gone off for a wonk.....my OBC reads 300 miles as of now and I still have a quarter tank left...go figure. Before the change I used to barely get to 240 if i let the yellow light come on. I dont stand to gain anything by this......to each his own....I am just posting this as a knowledge based on experience.....! Oh and I dont own stock in K&N.... . I have done nothing else in the car...old spark plugs, no tune up (my Insp II is due in three months), no engine modifications.

I drive on the 64/40 East west in St. Louis and if anyone knows that......its more like stop and go as opposed to a highway....lol.....so in these conditions trust me I was way happy with 240/tank.

[Ivan]

ive heard K&n filters suck. my car doesnt run as well as it used to when i had ther stock airbox. it's on my to do list to get rid of that pos kn filter and get the stock airbox again

[Hootie]

Sorry Ivan, you heard wrong. I've been using a K&N for the past 25K miles. I knock the debris out every several thousand miles and re-oil the filter once a year... works like a charm.

Sounds like you have a CAI with a cone filter though. We're talking about a stock box with K&N rectangle filter.