warminwisc

I have been running 87 in mine since spread on primo went to 70 cents. Never notice a lick of difference between 91. That’s just me not picking sides. My 2 each went past 200 k no cat probs or other.

Jabberwock

Here my experience with 10 year driving the LS. I drive like an old man so everything I say is based on that kind of gentle driving. if you drive the car hard this does not apply.
My car runs 87 octane just fine in cool weather, apprx below 80 or so degrees. Above 80 on hot summer days I have notice some degraded performance and once or twice some knocking going up a long steep hill on 87 gas. So when weather gets hot I run only 91 octane gas. Running 500 miles on an interstate in October the car runs just as well on 87 as 91 - no difference in mpg. I think this is because ignition is retard only when knock sensor fires and when the LS motor is loafing along (which is most of the time) it runs the same with 87 and 91. I have run 94 gas a few times in summer when it is available (usually not in my area) and mpg improves about 5% from 91 octane. I actually got 28mpg on a tank of 94 gas on a road trip with all interstate driving. So choosing to use 87 or 91 for me is about the temperature and type of driving involved, but most of the time I use 91 gas as I don't drive enough for the cost difference to matter.

AJT123

I run midgrade sometimes when premium is overpriced. It doesn't hurt the car, but it is noticeably faster with premium.

You can definitely tell a difference in pep, and how eager the engine revs.

It's an observation that I've always noticed, just sort of surprised at the performance difference and figured I'd share.

I'd say not using premium sucks 20hp away. The car just doesn't "wake up" as fast when you prod it like it does running on 93 octane.

Jabberwock

I have never noticed any difference with fuel grades unless it is super hot outside when I have noticed some knocking going up long grades. But I drive the car like an old lady.

AJT123

It's there, at least in my car. You really notice it if you goose it through 2nd gear, or when it downshifts to it aggressively.

I drive like an old lady to but I do enjoy the V8 and gun it a decent amount. I easily notice a difference in the way it accelerates on premium fuel.

If I were going to just loaf it around and never gun it, 87 would work fine.

Striker223

It's 100% noticeable, I had a tank of 87 since a station didn't have 91+ and it felt heavy and slow if I demanded full power. I redline quite often.......it's a good engine after all and fun to use

AJT123

It's a glorious V8. It's like you're getting a treat every time you drive.

Johnhav430

LOL me too. I have always used 93 since I got it in 2016, but I point out, my 1998 Nissan recommends premium, and that's the only way it would put out the 190/205 stated in the brochure (remember when torque was higher than HP, and why), is with 91 or above. I have run it on 87 for now 22 years. It did not blow up, nobody left a note on my windshield saying dang you're slow. As mentioned, I even topped it out at 137 mph back in 1999 (stupid).

And again I will use this example. 2015 VW GTI. Fuel door says premium required, 91+. 2016 VW GTI, fuel door says premium recommended 87 ok. IDENTICAL CAR. To say car performs better with 91 or 93, when it was designed for such? Yes. To say it's smoother and gets better mpgs? I have to draw the line there and say false. non sequitur. That's not what octane measures nor represents. There isn't more goodness in 93 over 87. It's about predetonation. Put 93 in my wife's GM designed for 87, it's burning money out the tailpipe and of no benefit.

warminwisc

In Wisconsin primo is 70 cents more so 14 bucks a tank on my LS with 210 k miles. I just had a wheel bearing done and power steering pump 50 k ago. That’s all the maintenance it’s had and roars when I hit the throttle on regular. If u spend the $ and yur LS runs faster great

My question is there any solid examples of premature wear and added costs running 87 gas that we know of?

Thanks it is Warminwisco been 90 plus for a week

Johnhav430

If your car is designed for 91 or higher, and the knock sensor is faulty, yes, that can lead to damage if using below 91. If a knock sensor is faulty, and a car is designed for premium, I would not use regular, until the sensor is addressed. On a normally functioning car, using regular in a car designed for premium, means it does not achieve the HP/torque numbers in the brochure, as timing is affected.

JffGRY706

I don't put in $5 or $10. I always fill up the car. And I try to use up as much as I can until just below the !/4 tank mark. Usually get about 17 gallons of good fresh premium. I try to get a small discount by using points from buying groceries, but to do so means not able to just fill up. To use the points I have to buy an amount ( $20 or $35 ) and I don't like that. Grocery store sells Philips 66 gas. Like warm premium is 70 cents more and price has not been adjusted since gas price has fallen. should be much less. Think cost per octane and really bad on wallet to run premium. I just don't think about it anymore. It still says premium unleaded only so that is the answer.

Striker223

If the knock sensors are retarding timing that already means knock has occurred and the sensors have been exposed to more vibration than needed and if you look up how they work that shortens their life. New sensors are $650 if I remember for OE plus damage done to the rest of the engine even on a very small scale.

I would rather pay for the better gas than the hassle if something goes wrong with the actual engine.

Johnhav430

I agree, and do too in the LS430, but as mentioned, the Nissan has been using 87 for 22 years. And knock sensor was replaced maybe 2015, I remember blood everywhere, really unpleasant. I would probably wimp out and pay someone next time in 2032 (nah the car would be a heap of rust by then). The other repair that causes bloodshed is a BMW corona light ring bulb. Pretty ridiculous.

YODAONE

Have read that the ECU will not fully advance, and, or retard ignition, but also enrichen fuel charge to prevent knock/pre-ignition/detonation, which, over time, makes engine susceptible to build-up on intake, valves and combustion chambers.

87 octane is a problem.

Anyone purchasing a Lexus should request fuel receipts to determine whether owner used correct octane.

AJT123

To be fair, though, some Lexus cars don't really require premium and it's just BS marketing.

Yes, my LS needs premium but not all do.

LX for example, engine is identical to Tundra and Land Cruiser motor. No reason on earth to waste money on premium fuel.

That's like $18-20 a tank. It's part of reason we decided to get LX and not GX (that and LX is just 1000% more everything for not much more money). GX has different compression than Toyota V8 so octane rating is debatable. I personally wouldn't plan to run regular for life in a GX. LX, I'll never put anything above 87 in. Who gives a s--t if it gets 13MPG I couldn't care less.

I don't care to drive a gas guzzler as long as it's regular gas it takes.