s2000zr

I don't see how some of you guys get 30+ mpg. I babied mine and barely get 26.5mpg. The only time I got 30 mpg was when I evacuated for hurricane. Sitting on the highway going under 20mph for 3hrs. I guess if your in California traffic You could get 30mpg.

gadgetman1

So, is there an official word on using premium fuel vs. midgrade or regular unleaded without damaging anything or voiding a warranty?

ggebhardt

Regular gas will get you slightly less horsepower. My dealer told me that the premium was used for an extra mpg or two for EPA purposes.

99% of all Lexus dealers have one underground tank of fuel and it is regular. So Lexus is delivering your vehicle with regular grade gas and it will be just fine.

Freds430

I have used 87 octane in my 2015 RX450h and 2013 ES300H. I have noticed no difference in fuel economy. I have used 87 octane in engines that have recommended premium for over one million miles and never ever had an engine problem. I always revert back to two MIT graduates that are car mechanics who had a syndicated radio show called Car Talk for 35 years.
http://www.cartalk.com/content/premi...egular-0#myth4

From the USA Today:
The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.

Burning regular when the owner's manual specifies premium won't void the warranty, nor damage the engine, even the most finicky automakers say. "You're giving up perhaps just a little bit of performance that a customer wouldn't really even notice, it's so slight," says Furey.

tgarons

We have a 2017 RX450H and a 2017 Highlander Hybrid. As far as I can tell, the power trains are identical—both have the Toyota 2GR-FXS engine. The Lexus calls for premium, the Toyota regular. As was mentioned above, the only rationale I can see for this is the slightly better EPA mileage for the Lexus This roughly reflects our real world experience: We've been faithfully following the fuel selection in both cars and over a couple of thousand miles of mixed driving are averaging 28.7 mpg in the Lexus and 27.6 in the Highlander. Since premium gas around here is 60 to 80 cents a gallon more expensive the regular I am inclined to switch to regular in the Lexus, however there is this dire warning on page 591 of the owner's manual: "If the octane rating is less than 91, damage to the engine may occur and may void the vehicle warranty." What's up with that? AFAIK Lexus isn't in the gasoline business. Why do they care so much?

ggebhardt

Regular will run just fine. The premium is all for the government EPA thing. You Lexus dealer filled your tank with regular before delivery. Premium is just wasting money.

Beware, this subject is like politics, and it argued over constantly.

pdaeng

Require premium gas is called brain wash.

I only use regular in my 16 450h Fsport more than 13k miles. No issue at all to use regular gas.
My long term mpg is 29.3 using regular. I do not think premium gas will increase anywhere from there.
As you said, RX 450h has the same engine as highlander hybrid.
Modern engines have the sensor to monitor the gas grade and change the timing. Even turbo engines have no issue, let alone RX's NA engine
Additionally, even knocking happened, that is when engine working hard, but hybrid engines do not working hard.

So, I can see no reason to use premium gas. Just waste of money.

Another observation is that Eco mode use more gas then normal mode. LOL

Htony

I always fill with Shell premium. There must be a reason when owner's manual specifies premium gas. Design engineers ought to know better than us. I drive 450h just like any other car. When I had Bimmer X5 which has 85 liter fuel tank, I used to fill up every week. 450h has 65 liter tank and I fill up every 10 days, upto 2 weeks. I always fill up when fuel gauge shows 1/4 full.

ggebhardt

Using premium will not harm your vehicle and you will get a few extra horsepower to boot! It is just not required.

Enjoy! These are great vehicles.

wa3cuj

I have a 2013 RX 450h. For the first 7000+ miles I used premium and I averaged 27.058 mpg. I then switched to mid grade and now have almost 46k miles on the vehicle and my overall average is 28.469 mpg.

Yesterday I finalized a deal for a 2017 RX 450h for my wife and will pick it up on Saturday. I asked the dealer what gas to put in it and he responded that you can run regular in all of the RX's with no problem.

Here in Pennsylvania, the difference between regular and premium is .60/gal. That's about $8.00 with every fill.

shric

Thanks to the input of the folks here. I started to fill up with Sunoco Regular and got 29.5 MPG on my first tank. Will stick to using regular unless expecting to haul 4+ passengers + luggage.

jonmanch

I have a RX450h and use 87 octane with no problem. The salesman told me that I could use 87 as that is what the dealer gives you when you pick up the car with a full tank, and the dealer only puts 87 in all of their demo and loaner cars. Have not had any lack of engine performance or noise.

gregjhonda

My 2017 RX-450H came from the dealer with 87 octane gasoline. It runs fine that way! I do get about 10% better fuel mileage on some premium gas lately but I suspect that some premium gas is non-ethanol at my local Shell gas.

The Lexus/Toyota CVT is nothing like the rubber band like units found in cars like the Hondas and Nissans. There are no rubber or metal belts. Instead the Lexus CVT uses planetary gears and electronic field coupling in the transmission to change gear "ratios" and start the engine in a split second. It's the smoothest and most exhilarating transmission I've ever driven. The steel belted CVT in my Maxima was real decent and even had simulated shifts but this Lexus CVT blows it away. You owe it to yourself to check out the many YouTube videos that show the inner workings of the Lexus/Toyota CVT and test drive one before dismissing it as just another cheap alternative to convention gear shifting automatic transmissions.

Elation

That does not sound good.
GS, LC, IS, 450H....They REQUIRE Premium fuel.

ericsan13

I'm surprised this hasn't been posted on the thread already. Here's the excerpt from page 591 of the 2016 RX450h Owners Manual. If you're not experiencing knock, which a modern engine knows how to prevent, you should be fine to use 87 as long as you don't notice performance degradation. It is only "REQUIRED" for "optimum engine performance".

In my area I have the choice between 87, 89 and 92. I use 92. It's a luxury car, why cheap out I say.