I have the idea to fill up my tank with premium, and then when it gets to halfway i fill it back up with regular...a friend told me i can buy a bottle of octane booster from the store for a few bucks (maybe cheeper buying in boxes of 10 or something like that) and you should come out a head a few dollars each fillup without sacrificing octane. but over the years that you have the car and as many fillups as you will likely have it will be worth the trouble?

Have a 2007 FJ part time 4W with all the extras. I did some research and found a copy of the release from Toyota stating that 87 percent Octane was acceptable but performance "could" be effected. I've been using 87 octane for a few months and actually the vehicle seems to run better. I track all my fuel versus milage and my last tank got 23.3 miles per gallon. I do drive with a light foot on the pedal but always get where I'm going. My mileage is both city and higway sometimes carrying a kayak... My FJ stands for Fishing Junkie..............

Has anyone tried an aftermarket air intake system to improve fuel mileage?

ive had my fj since it came out. i only run premium in it. it runs perfect with 15k on it. as for me, i paid too much for my truck to go on hearsay that regular gas is ok. we must all face reality here. it's a truck. a big badass truck. not a prius. so is it worth possibly destroying your car by getting cheaper gas? also please furnish us a link or a copy of the toyota report that says this is ok- for those who have read it. i have never been across this article that's supposed to be out there.
also in regards to the ques.{anyone tried an aftermarket air intake system to improve fuel mileage? } according to consumer reports either april or may 2008 they have tested these-used a product called vornado ) and resulted in worse gas milage. good day fellow fj cruisers!

sorry had to edit

Im buyn 91 octane at Sams Club for 4.01. the 87 runs about 3.80. I paid almost 29K (tax included) for my rig........based on compression and the fact that toyo wont actually release a tsb on this tells me to not mess with the engine-pay the 4 bucks more, and give the FJ what it wants to eat. Also, if you want optimum MPG-Autoweek just had an expose this week that showed almost a 400 dollar yearly savings by using premium gas when rated as the gas runs more efficiently. So......you spent good hard earned greenbacks-if you fill up three times a month your only saving about 15 bucks tops-dont chance it.

John in Sacramento

I use the premium also, it's not that much more money per tank to fill up.
Only the best for my baby!!!!!
I think using anything less than premium is like having an Fj and not letting it play. That's a sin!!!! It was made to play and I think that Premium fuel is like a well balance diet for my athlete!!!!

__________________
Mrs Crow from Ohio

Im with ya miss crow!

__________________
John in Sacramento