Cabin & Engine Air Filters

richromero · October 3, 2010

Hi Everyone,

I just hit the 30K mark on my '08 GS305 and had to get new tires and did the 30K service. I decided to change the air filters on my own as the dealer charged ridiculous prices for the filters (i.e. $105 for the cabin air filter installed). I bought a Fram cabin air filter and a Fram engine air filter. When I put in the Fram cabin filter (it was one of those with the baking soda added to freshen the air for $20.00 and it was much thicker material than the OEM) it seemed to cut down the air flow for the A/C and also made a whistling sound in the glove box. I tried flipping and same result. I ended up exchanging it for a plain filter that looked very similar to the Lexus one for $10.99 and it works great.

My real question is this...after installing the Fram Engine Air Filter...I've noticed my gas mileage has gone down (according to the Avg MPG display in the car). I'm averaging about 1.5 MPG less per tankful. I'm wondering if the engine filter is also restricting air like the cabin filter? Now I also changed tires for Michelins but I can't imagine that has anything to do with it. I used to use Fram for everything in the old days when I used to service my own car (many years ago)and never had issues. Has anyone heard of any issues?

I'm considering switching the air filter for a K&N but read a rating on Amazon that someone had their "MAF" on their GS350 (I'm guessing Mass Airflow Meter?") go out because of the oil. I've used K&N in many cars and never had a problem.

Any thoughts?

1990LS400 · October 3, 2010

Thoughts? Stay with OEM filters. Honestly, I don't know how K&N stays in business ... sooo many problems reported with their products on car forums -- maybe K&N is an "urban legend" thing.

Look at the price you can get and what is included in a "30K service kit" for your GS350 from Sewell Lexus by registering with them with your member name from this or other Lexus forums. Or you can buy the parts individually.

DavidN · October 3, 2010

Much, much more likely the tires, however, filters may be contributing. Check America's Tire for reviews of the tires you purchased. Overall, the remarks balance themselves out so one has to read into the reviews somewhat to determine what is really going on.

Good luck with this.

richromero · October 4, 2010

DavidN - Thanks for the advice. I did look them up on America's Tire (which coincidentally is where I bought them) and there were hundreds of reviews. I only read the first few dozen and in there was someone complaining of losing 2 MPG. In all my years...that's the last thing I considered when buying tires....go figure.