tripplej

I have a 2006 LX and while waiting at the gas station, I just happen to be waiting in back of another LX.. The guy in front of me was filling up his LX with regular gas and I asked him if he ever had any issues due to the regular gas and he said never!

I have always used premium gas and am wondering if premium gas is really necessary or just an option?

Any idea as to whether regular is sufficient or should I use premium for city driving?

thanks

Lexus49

TrippleJ,

I noticed a lot of people have their own opinion about the quality of gas they use for their cars. I also noticed these people are not Petroleum Engineers to safely advise others on what to use. With that said, your safest bet is to follow your Lexus manual and it's requirements.

I have a 2001 LX470 with 103,000 miles and I have never put high octane gas yet it runs like day one. My manual recommends 87 octane gas only.

Here is a fact:
If your manual states "recommended" - you can use either grade gas.
If your manual states "required" - you USE only the octane it states.

CAUTION: even Lexus dealers sometimes get this info wrong and they all tell you use high octane. Your manual is you best and safest bet.

-Lexus49

tripplej

thanks for the reply.. I will have to consult my manual.. So far, I have been using premium but if it not really "needed", i could save the money and use it for something else like a big 65" led tv.. (i can dream right!!!)..

Tnorling

My understanding is that Premium fuel will defeat the negative issues caused by Ethanol.

Kira X

iTrader: (24)

That's interesting. I always assumed that the LX's used premium. I use premium in my GX.

tripplej

I searched online since i don't have the manual handy and found it..

http://drivers.lexus.com/t3Portal/do...1U/pdf/gas.pdf

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

So, what does this mean --- select octane vs research octane?

I normally go to Shell but not sure if it is select or research..

AKoch

difference in measurement methodology:
- in the US the 87 octane rating is same gasoline as 91 rated in Europe
- 91 in the US is the 96 rated in Europe

tripplej

Thanks for the information.

I went by the Shell, and I see the below.

87 - regular
91 - in between one
and 93 - for premium..

So, I should not be using premium but instead should be using either the 87 or the mid one 91..

This will save me more money but with the higher octane 93, performance will be better per the manual..

But of course, the 91 they mention in the manual is the mid one so I don't have to go premium per say.. Just one above the regular one.

decisions ... decisions..

tank97

91 should be ok coz here in vegas, we dont have 93 octaine and 91 is our highest one here and that's our premium..lol. when i saw ur location tx, yea they have 93..

87 reg
89 mid
91 premium

Kira X

iTrader: (24)

That's how gas in Oklahoma is. There are a few 93+ gas stations, but they are rare. It's mainly 91.

osomoso

Got a local 7-11 that has, 87,89,90,91,93. Take your pick, they are all still over priced.

V8_Fan

Dang, I haven't seen 93 octane since Texaco! I use 91. 87 will work, but you lose performance (the chip will adapt to the gas and adjust the timing). The reason why these premium cars recommend premium gas is to guarantee a certain level of performance (usually, the advertised engine output depends on a certain compression ratio that you'll achieve with high octane gas). In my old 4runner, I ran premium (91). Why? Because I got much better fuel economy w/ 91 over 87 (it was like 10% better) in that the acceleration was noticeably better, which resulted in me using less throttle for the same acceleration. In the end, it was about a wash. At least I didn't have to gas up as frequently w/ the 91. In my Honda CRV, I tried both premium and regular, and it didn't make any difference. In CA, I'm convinced they achieve the 91 octane by increasing the amount of ethanol rather than further refining the gas. I'd always get 2 mpg worse on CA gas than AZ gas (and this is AZ gas that says up to 10% ethanol).

AKoch

Hey, compression ratio does not depend on the gas octane number And is fixed for the given cylinder volume/piston travel. The ignition timing does get adjusted based on the knock sensor output, so lower octane fuel results in lower power output.

Toys4RJill

Seeing that the LX470 uses the same engine as the GX470, 4runner which all run on regular gas, I can't see why the LX470 won't be fine on regular.

north100

Most modern engines with electronic ignition maps can compensate for lower fuel octane by retarding the timing based on the knock sensor readings - prevents pinging, or preignition that damages the pistons, mainly. I run regular mostly, but in hot weather, where the propensity for pinging is increased, I run mid or prem. grade. I occasionally run premium when I stop by a station whose premium has some 'cleaning' additives in their fuel.

Final note, I have heard discussions that running premium give better fuel economy, and offsets its higher cost - anyone have some actual numbers on this?