With gas prices rising for past few weeks i have started to put in regular in the GX... must say that i'm starting to notice some power loss. I really don't feel like spending $50+ on filling up my tank on supreme. this really sux.

Yeah I know. Chevron is charging $2.67/gallon for Super Unleaded here in southern California. This has got to stop. These oil companies and the oil producing countries are making a killing off of us. I've used the premium unleaded gas for years and it helps the car's performance and keeps the engine in tip top shape. Now with these gas prices I've switched to regular as well. I'm still waiting for the day when gas will be under $2 a gallon.

careful. i did that before with my accord, got the engine ping. i switched back in 92 on my accord becuz i came from Joplin Missouri where the price of premium was less than $1 per gallon. when i transfered to california, the price of UNLEADED was around $1.35 a gallon.

i don't know if it will occur in these engines, but i always warn people of the engine ping problem.

From what I have read on this board through searching...Our 4.7L is identical to that in the Toyota's and they only recommend regular.

I have been running regular unleaded for about 5,000 mile with no noticeable loss in performance, smoothness, or any hint of pinging...I will probably continue to run regular unleaded from now on.

When I had my GS400 I always used premiuim; but this vehicle seems to be different.

i almost went into shock when i saw some of the gas prices around the states on tv yesterday.. $3.00 for gas?!?! holy crap.. even the $2.67 sounds crazy...

i've been very fortunate... $2.15 for 93 here on the northern de/md border..
even lower in south jersey..

once you get passed the mental block the truck will run and perform the same, ever hear the old saying my car runs faster when it's washed and waxed

In that case, I will need to go out and buy some racing stickers too for some extra horsepower! hahaha

We run regular in our '04. Engine runs fine. Manual recommends regular. 15.6 mpg average in mixed suburban driving. The GX is more economical than our Ford Expedition it replaced (11 mpg).

well, it says in the manual "Premium Fuel (recommended)" .

Keyword, RECOMMENDED but I just put in regular, especially the price of regular is already at least $2.40

does not say recommend, lawyers wrote it and Toyota can't explain it octane rating of 87 is fine, for added performance use higher octane

To be honest I can't find the added performance and Toyota will not tell me how I find it, they only seem to read me line after line from a manual, the only thing I managed to accomplish with my driving using premium was to burn more in the same distance, my mpg went up 5mpg with regular, just to give you an idea I hit redline often, very often, it's the only way I drive.

I save an average of 7 bucks a fillup with regular, main reason and I saw no difference, thats my opinion and what others put in their vehicles is fine by me,

I do find it funny when I pull in to fillup and a civic is pumping premium

2005 GX DOES say recommend:

cut and paste from manual


Fuel selection:
Select Octane Rating 87 (Research Octane Number 91) or
higher. For improved vehicle performance, the use of
premium unleaded gasoline with an Octane Rating of 91
(Research Octane Number 96) or higher is recommended.

your right, they do recommend the use of a fuel with an octane of 87 or higher

The difference in gas mileage (if any) is not going to make up for the extra $.20-$.40/gallon you'll spend on the premium gas. It's you're money, but you might as well flush a $5 bill down to toliet everytime you fill up as give it to the oil companies.

As for "increased performance", we are all talking about GX470's here right? If you were looking for performance you bought the wrong car. Don't get me wrong, I love my GX, but when I want performance I hop in my E55, which does by the way require premium fuel. I don't drive around in my GX believing I'm in a hot rod. Any additional performance perceived is more likely due to a tailwind, or a downhill start than it is to the higher octane.

I told you! If there's one thing I would read in any owners manual, the first thing would be what kind of fuel is Required and I decide from then on if I will go with the Recommended.

Check out www.losangelesgasprices.com . It has links to similar sites in other regions.

Recently I went to a Lexus New Owners Clinic given by Longo Lexus (nice, evening, catered event). The service guy insisted that premium fuel was the way to go....that premium gas is of higher quality than regular. He has no financial incentive to lie, so I give what he says some credence.