Originally Posted By: Hessam
Originally Posted By: 04SE
Originally Posted By: Shannow
Originally Posted By: Hessam
they are not worthless... if you don't drive on dirt roads, and keep most of your driving to paved street/highways, they will filter fine. Their filtering efficiency actually improves with time.
I got one in my LX450 since about 119K miles, and my engine is doing fine. no problems whatsover, and i have never even replaced or cleaned it... it's getting about time I do something about, and thinking about going back the OEM paper filter, but I am not sure I am ready to give up my 16 mpg that I get with my K&N
How does the K and N improve your fuel economy ?
I'm assuming that you are driving at normal highway speeds, and the the throttle plate is mostly closed for nearly all of that, so then how can the K and N possible give better economy, when it's the overall restriction between air intake and inlet valve that controls your airflow/load ?
Doesn't add up.
Because a multi-million dollar advertising campaign says so? Along with fancy graphs and 'estimated' HP/TQ increases.
No because I actually measure my MPG for every tank of gas. My average has been 16.2 with the K&N filter with about 75% highway and 25% city driving. with my old OEM filter my average was 15.1 and the highest tank I ever got was 15.8.
The K&N can have an increase in MPG in some engines. They engines they work on best are the old school engines, without a lot of modernized computerized management. To best of my knowledge even though the LX450 does had fuel injection, it's a very basic FI set-up and the main block is essentially an old Buick I6 from the 60's which had been used in most landcruisers until the mid 90's.
So if I understand you correctly you are saying that with an oiled gauze filter you've increased your mpg by 1 mile over the stock paper element.
What utter nonsense.
For starters on a stock engine the oem intakes aren't restrictive. Unless the engine is modified such as heads,cam and exhaust the stock intake isn't isn't anywhere near its peak cfm,and unless the engine is being operated at high rpm there isn't any chance the airflow is inadequate.
And an intakes design is centered around air velocity. So a small engine with a huge intake volume has the air travelling at low velocity and that actually makes the engine work harder to suck. A smaller intake will increase the velocity of air travelling which reduces the resistance and increases volumetric efficiency.
Intakes and exhaust are a balancing act. If the intake is too big part throttle response will suffer.
Anyways believing the filter increased your mileage by 1 mpg is nonsense.
A headwind has more effect.