uncle_el

i paid 2.82 today for 91 here in cali.

PureDrifter

iTrader: (10)

my price is about 3 weeks old now, im going to go fill up today

damon

Let your ears be your guide. If you put in a lower than premium octane fuel & you do not drive your car hard enough to hear any knocking/pinging then you are not doing any damage to your engine.

Higher octane fuels do not burn any cleaner so don't believe that crap either. I do notice a performance difference when I use lower grades but it is no big deal. On long Highway trips I will frequently use lower octane grades since it is an easy load on a 8 cylinder UZFE engine.

wkinley@gm

I did a search thinking surely this must have been discussed at some point, but came up with nothing.

With the price of gas are any of you guys using 87 octane? I have a '98 LS400 and pretty much have stuck with premium, as recommended, but occasionally I may cheat and top off with regular, trying to keep the octane 91 or higher. I have heard people say listen to see if it pings, but the car is so tight I would have to have the windows down to hear a ping.

My son-in-law is a tech for Saturn and tells me it is a waste of money to use premium, that there is a computer in the electronic ignition that makes the proper adjustments to compensate. What doe's he know, he works on GM junk??

I would like to hear some discussion on this.

LiCelsior

iTrader: (32)

lol, i personally use 93 since lexus recommends it but i've heard ppl say they feel the difference when using 93 compared to 87.

LexChamp

I personally use Premium, with sometimes going 1/2 and 1/2 with Mid and Premium but never 87 on the LS. However, I have an Acura Legend which it had always used Premium but when I bought the LS, I started using low grade. It has made no difference in the performance of the car. I just feel better using Premium in a vehicle that I truly appreciate. I really don’t mind spending the extra few $$$ for the LS. It gives me piece of mind.

PureDrifter

iTrader: (10)

meh, ive been using 90+ (91-93 iirc) for the most part, i find that anything under seems to give me slight knocking on acceleration.

pito

Yeah 87 gave me knocking as well. WE mostly have 87,89,93 sometimes you find 91 but thats more rare.

ANstyle

It's a Lexus.....use premium. ;-)

But seriously I would shell out a few extra bucks to make my car last and keep it healthy. It's worth it.

TJW98LS

iTrader: (1)

I wouldnt even attempt 87 in my car. I run 93 everytime I can. If I come across 91, ill put a little in to get me to another station.

Back when gas was about $2 I put 87 in my lincoln ls once by accident...a FULL TANK accident. I got up on it to merge into traffic and the car sputtered and hesitated. Thats when I realized on the reciept that I put the wrong damn fuel in.

I think that was my worse average MPG Ive ever had...11.5 MPG just trying to get rid of it.

steveski

For your car (1998) you may be right that the computer can make adjustments. On my 95 I do not believe this is possible. My Father-in-Law has a GS with VVTi and he uses mid grade (no knocks or pings).

I thought about using 87 octane with the price of premium in Houston being around $3.15. However I never did. The big reason is I may only save around $5 per week. Additionally, I don't have VVTi and I do not see how my computer can adjust thie timing, etc. to compensate for lower octane. For me it is not worth the $5 difference so I will keep using the 93.

For you however, you should give it a shot since you have VVTi. Let us know how it works bro.

illcelsior

I wouldn't bother using less octane. It may pull timing in the midrange to counter the pre-ignition.

Since switching to the Blitz ECU, I must run 93+. The timing is advanced over OE ECU.

skperformance

iTrader: (6)

All motors from any manufacture can adjust the timing for lower to higher grade gas. If you use lower gas it cannot advance the timing they way it was designed for to be used in conjunction with 93 and up octane. You may never hear a ping but it does not mean it is not happening. Older cars with wider valve overlap will be more easily heard compared to a tight tolerance motor like ours. I have used lower octane and do once every 6 months to let the motor make adjustments and calibrate itself for the higher octane when i switch back as it will not have to retard the timing as much. Lower octane will burn better and makes a very different exhaust note on my car . As i use that to know how well my car is running.

So all in all , use it once in a while but not daily , it is easier with lower compression motors but definitely not ours.

wkinley@gm

I really haven't used 87 octane much, mostly just to top off attempting to keep it above 91 octane. That said, I have put in full tanks of 87 octane occasionally on trips with all interstate driving and haven't noticed any difference. I tend to agree however, that the 4-5 bucks per tank is no big deal and probably will continue to top off 87 octane when the tank is 2/3 full of 93 octane.

Have any of you noticed that some stations have increased the differential between 87 and 93 octane by an additional 3-4 cents? I wonder if this is an indication of future pricing.

skperformance

iTrader: (6)

Another thing i noticed with my LS is the shift pattern for the tranny is really sloppy and it will keep switching gears to compensate for the lack of ability ot adjust the timing and keep power up. As well i find it sluggish with much less power.