AL13NV8D3R

For my 2020 RX350 fsport i find using 93 premium 10% ethanol will give me that extra bit of power i actually can feel but call me crazy but i feel the transmission shifting is not as good. When the car is in Radar Cruise control and the car in front moves out the way, the car will jerk while downshifting sort of like a slipping feeling, alot of engine noise but a delay in accelleration.

So i tried a few tanks of 87 regular fuel with 10% ethenol and this problem goes away. But as soon as i go back to premium the problem comes back. And this does not change regardless of different gas stations. What gives?

ravenuer

Don't know why that's happening but, it sounds like an easy problem to fix. Cheaper too!

Freds430

Absolutely true. Watch YouTube clip from CBC on gasoline grades. Test show no benefit for using premium no better mpg and no better acceleration and no benefit to the engine.

LexusORD

Are you saying this for all cars? If you are, you're completely wrong. Also, if there is no benefit or no change, then why does the ECU have to adjust the timing on the engine? If it's adjusting the timing due to lower grade gasoline, then something has to give performance/efficiency wise. It could be minimal with some cars, something not noticeable, but for other vehicles it could be noticeable. If you have an engine that's built for 87 octane only with low compression and low power, it's a waste to put anything higher. If you have an engine that's performance oriented but can still run safely on 87, then there will be a difference. It's up to the owner how they see fit, and whether or not they care about any possible benefits. If you have a car that's higher performance and it's recommended, then you will notice it and should put in 93. If you have a car that's tuned for 93 octane and you use 87, you will damage the engine. Especially a forced induction vehicle. I have a YouTube clip as well posted above that's very informative.

jcg0324

I just tried a tankful of 93 octane in my 2017 RX for the first time. It did seem like the car had a little bit more pep than usual. No difference in shifting or anything else. Definitely not worth the extra $$$.

Freds430

Driven Lexus and Acura models that require premium using regular for over one million miles. Absolutely confirming what the video from CBC study reflected no engine problems, no difference in mpg and no difference in acceleration. Wondering how much $$$$$ I have saved.

LexusORD

Lexus and Acura, and probably several other vehicles can run regular, the manufacturer wouldn’t say so if they couldn’t. You’ll still have a trade off. You may not feel it on your ‘butt dyno’, or notice any significant mpg difference, but there will be some. It’s actually provable on a dyno. In the Lexus 3.5 it’s something like 7 horsepower…not something you’ll notice. Mpg wise it’s probably a similar difference that’s not noticeable. There’s a reason why Lexus based their numbers on premium and not regular, they want to market the best possible numbers no matter how minor the difference. What may benefit over the long run, and long run is 150k plus miles, is less carbon build up in the engine. Premium does have more detergents in it, and in a higher compression motor like ours it burns up cleaner. That’s provable no matter how many times you say it isn’t. I haven’t seen this CBC video, but I posted one above that actually breaks it down. I have read articles that did actual dyno testing. There are a variance of differences in this too, depending on the engines. Our vehicles don’t truly benefit like some others. Sometimes what manufacturers recommend isn’t always ideal, but it’s great marketing and they are able to avoid liability. It’s like the 10k mile oil change Lexus recommends. Sure you can go 10k miles, but over the long term it will increase your odds of sludge and lead to oil burn. You’ll have people who never do a trans service or coolant service, and say it’s a waste of money because they never do them and never have issues. Personal experience isn’t always gospel. You’re right in the sense that you won’t notice or feel the difference so you don’t see any reason or value in paying for higher grade gasoline. The technical and mechanical person in me who knows there are some benefits, however minor, make it worth it to me even if it’s not something I’ll notice.

jrobe

In my area, the price of premium fuel today is 74 cents higher today than regular gas (26% higher). When I do the math for myself, I would spend about $3000 more to use premium gas over the life of my Rx350. I would have to gain an additional 24,000 miles of life in my engine with premium fuel just to break even.

It is possible that there is a slight engine benefit to premium fuel but it nowhere near a 74 cent per gallon benefit (or 26% higher cost benefit). The price difference between premium and regular fuel is too higher to make the math work. Premium fuel is a sucker bet when it is optional. You would be better off just getting a brand new RX engine 24,000 miles sooner.

Quantum501

wait....some people don't listen to the Lexus engineers?

GSFRX350

Is that price difference common in N America? Here in Australia we have three grades, Standard(91), Premium 95, Premium 98 and the 95 is around 5% more expensive with 98 another 5% on top of 95.

Randyp1234

Here in central Illinois, that much of a price difference is not normal. I think Premium is maybe 15 to 20 cents higher. I'm not real sure because I never buy premium.

mikemu30

.60/gal diff here in northern NJ.

TechNut

Right now at my nearby Chevron station, exactly 20 cents separates each grade here in SW Idaho. Therefore, premium will be 40 cents more per gallon. I wonder if the differences are a result of different tax structures. I wonder if higher octanes perhaps have a higher tax in some states since the requirement/recommendation is often associated with less economical vehicles?

autotech13

Everything here in the USA is a rip off, including the oil companies!

toyotaman7

In canada Mid grade is about 10% more and Premium another 5-10% on top of that.

2016-2022 RX 350 requires regular Fuel as per Lexus design and stated in the manual. I find it would not make a difference in everyday driving.

i do however use premium when towing my trailer close to the cars capacity. I find it has a little bit more power to tow the trailer. The engine does not have to adjust timing compared to premium and can produce slightly more power (the difference between highlander and RX specifications); under heavy load when power is really needed.

Any other time I find this engine is really relaxed.