I've done 3 tankfulls now with the K&N replacement filter element in my 99 GS4. My average MPG's went from 21 to 23. I drive about 80% highway and usually 70-80MPH on the highway. My Lexus OEM filter had about 10K miles on it before I changed it out. As others have said before, this is a no brainer minimum mod for $40. It took my 14 yo son and me 5 minutes and most of that was opening the package and reading the directions.

Next weekend I install the L-Tuned Mufflers. This car needs to growl.

Murph

 

Murph, be careful. Keep your eyes on your keys; your biy will be eyeing them even more with your growing mods. Been there, did that myself. Not saying anyting about your son, of course.

 

Hi Dex,

I remember what I did with/to my Dad' s '65 Mustang convertible as well. It had a 289 and a 4 barrel carb. He was also a car nut. Hereditary I guess. Any way I've done 2 things. First I got rid of my last in a series of weekend "fun cars" That was my Z28 Triple Black Convertible. My wife was adament about that as I also have a 19 yo boy and 17 yo girl. The second thing I did was buy a used Saab 900S for the kids to drive. Looks sporty but has dual airbags and a 2.3L 4 banger. So since I can't have a second fun car anymore, I got the GS400 and away we go!!!!

Murph

 

Well done, young apprentice. I just took a LONG trip (700 miles), all highway, going, er, 'quick', and my nav computer says I got 24.3 mpg!

 

Murph,

Where did you find the K&N replacement filter, if you don't mind my asing????

Thanx

 

Take your pick

http://www.knfilters.com/online.htm

It's easy....Murph

 

Thanks, Murph.......
I tried all the sites and they don't appear to have a filter for the GS300. Guess I actually have to pick up the phone.

thanx

 

K&N does not sell one for the gs300 but TRD does. but it's $80.00

 

yea, I've seen that one on the TRD site. 80 bones seems like a lot for a drop-in. I'll prob just break down and get it anyway.

gs300-101 - are you the one who just put the SSR GT1's on your ride?? if so, saw the pics.....all I can say is... SUUUUHWEEEEET!!

Eric

 

sorry wrong person.

 

sorry dude, that was kevs....

 

I will be putting in a K&N in my G4 very soon, I was wondering if your "seat-o-the-pants" meter could detect any improvement in acceleration as a result of reduced intake restriction.

Ihave K&N's on my Turbo-Diesel Ford P/up & my 911 Porsche and was happy nwithe the results.....

any good news....?

 

Ocnbrzz,

I really didn't feel any power difference. Going from 300 to maybe 305HP is not really noticable. However I rarely jump on it hard anyway except for when I need a power rush. If you want noticeable power you should do the K&N or others Intakes. These have been discussed at length so you'll see a lot of good debate on these when you search.

Also incidently I did the L-Tuned mufflers as well. I now have done 3 more tankfulls and have had 24MPG once and 25MPG's twice. So the "breathe in-breathe out" additions gave me an average of 3-4 more MPG's. Plus the sound of the mufflers is intoxicating.

I hope this helps.

Murph

 

Thx for the reply Murph,

I agree w. you, that increasing the engines ability to "inhale-exhale" is the first step to increasing power and economy.

Fyi, I am also looking at an exhaust upgrade, heck the wife even thinks the exhaust tips look too small & wimpy!!!

Thx again.

 

hmm ... for a while I was tracking my mileage as well ..

usually i average 16-18 mpg cruising around the area ...

and my best mileage was a high speed run from LA to SJ area...
lot of 80 mph + cruising , as well as a good number of 80 - 120 accelerations ...

that ride was about 24 mph...