I use to run regular on my GX and RX, but I use premium in the GS because the compression ratio is higher.

 

could you try premium on your next trip? just curious...
feel free to send me your bill

 

How about you trying regular on your next trip and report the results.

 

The Bill for using regular may cost a lot more than using premium

 

It depends. I don't engage in drag racing, and have never floored the accelerator from a stop. If I was that type of driver, premium would be the way to go. However, if I was that type of driver, I wouldn't be driving a Lexus.

 

When you get up to around 12:1 compression ratio range, you should really use 91 octane. If use the recommanded oil type right, so why not recommanded octane.

 

My wife has been putting mid-grade in her GS300. I put in premium every time I drive it so it's getting both. I did read in the owners manyual that it was okay to go to mid-grade so I ain't sweatin it.

For the GS350, nothing but premium. I've used premium in every car I've owned, even the Nissan Sentra. SOme say it's dumb...I say mind your own beez wax. My grandad said to always use the best gas and I always have.

 

I don't think anyone in the automotive industry wants to change. No the auto manufacturers or the people who make parts, the people who repair, the people who make gas....no one....and that's disgusting to me.
We live in an age where we should be driving cars with the capability to fly or use the road (google the Skycar).
We have the technology to develop clean electronic machines and we're still using combustion technology. It's just disgusting to me that greed and power rule the day.

 

Back around 5-6 years ago, when gas was $1.10 per gallon, and when I had an Acura TL, I did extensive experimentation with premium (recommended by the manufacturer) and regular gas.

I found that I was getting about 10% worse fuel efficiency with the regular gas vs. premium. Given that the premium gas at that time was 20 cents more expensive than regular -- or about 20% more expensive -- it made a lot of economical sense to use regular gas instead.

Fast forward to 2008: the regular gas here is $4.00, and premium is $4.24, making the price difference only about 6% down from about 20%. I have not tested the effect of using regular gas in the GS, but I would bet you loose at least 5% in fuel efficiency. Given the current lack of significant price differentiation between regular and premium gas, it makes zero sense to use regular in a vehicle that is optimized for premium gas.

 

It's "optimized for premium gas" to achieve the best performance but there is no need for best performance during regular day to day driving.

 

To me this just like using the cheapest oil, car wax, or any other item for you car. If they told you they just changed your oil with valucraft brand and detailed your new car with Nu-Finish because it was the cheapest stuff they could find most people would be pretty upset. Regardless the engine was designed, tested, and rated to use premium fuel otherwise they would not have put that information on the car. I have a friend who lives in ATL and he has an 2003 Infiniti I35 which he has owned since it was new and the first two years he used premium but since then only regular. When he drives through the hills and the engine is under a load sometimes you can hear pre-ignition especially during the summer. I just don't see where there is any benefit of using regular. I sure everyone in this forum pisses away the difference in the cost every week on something useless or stupid.

 

heh reggie that's exactly how i feel. we've been practically using gas ever since the car was invented..its time for a change. and also doors that don't open out but instead just retract into the bottom of the car. LOL look it up it's pretty cool

 

Saudi Arabia just agree to increase production by 500,000 barrels a day. Soon oil price will stablize and all this talk about alternative fuel source will be forgotten. Seems like we been here before.

 

There is very little difference between premium and regular. Premium has an octane booster mixed in at a higher percentage than does the regular fuel while your mid-grade fuel is a mixture of both your regular octane & higher octane fuels (do you ever see a fuel truck carrying 3 tanks????).

The US produces a cleaner burning fuel product than do most other countries, since the automobile is a GLOBAL product most auto mfg simply place the "use premium fuel" stickers and warnings on all their cars. I would venture to guess it's more appropriate for those countries producing a more "dirty" fuel product.

The premium fuel product, while it does contain a higher octane, while it does add a few more HPs (if you need to shave down your 1/4 mile time between stop lights) has, in this country, been used more as a marketing tool than anything else.

It reminds of how here in Calif they say "ARCO" gas is sssshhh!ttty gas, don't use it. Well kids, there is only ONE (1) (uno) way to refine oil into gasoline and every oil company uses the same process the only difference from one oil company to the next (here in the USA) is the additive they put into their gasoline (Chevron uses Techron, Conoco Phillips uses PROclean, BP/Amoco uses ULTIMATE). Take out those additives (which essentially all do the same thing) and you have raw gasoline which is the same from LA to NYC

While I won't go into a dissertation about the process of refining oil to gas I will say I worked for Atlantic Richfield Company (ARCO) [now BP] here on the west coast) for 6 years, Unocal (now chevron) for 5 years and Conco Phillips for 7 years all in refinery operations. I know how some of you kiddies like to bash one another so Im just saying.........I know just a little bit about this stuff.

Edit: there is a different formula used in the winter season so some may notice a change in performance during that time of year. When exactly they (oil companies) change over, I don't know but you will notice more of a "sulfur" smell coming from you engine when the winter mixture is introduced to your engine. Very noticeable when you "gun/hammer" the throttle like in a passing situation


late

 

Armand,

Thanks for the good info.

JerFitz