Who's "they?"

They certainly didn't try this on a Supra. Mine went from 18 mpg on 93 to 12 mpg on 91 (even after doing all the things any prudent owner would do to reduce octane sensitivity.) No damage? Sure. Decent gas mileage? No way.

I ended up putting in 4 gallons of 100 octane unleaded with 14 gallons of 91 "premium" to get back to 18 mpg around town. It was actually cheaper.

 

i would just like to add...that i originally got 87 because that is all i could find...after waiting for gas for 20 min and finding out that all they had was regular i wasn't about to just go home...will continue filling up with premium from now on....

 

I own a IS350 2014awd and was looking into regular vs premium gas. I know there are lot of threads about this already but wanted to share my small test. I used to own a 2007 IS250awd and i always put premium on that car, I now have the 2014.


ok, my 2 canadian cents. I filled up with regular gas on Sunday Dec 2 from empty (gas light was lit up). Cost of regular at the time was like 98 center per liter (records low now a days). I did a quick calculation and if I was to buy premium at that time I would have spent 9 dollars more.

Let me say that I drive mostly highway for work and I typically fill up every 4-5 days. My style of driving is not aggressive at all but on occasions I step on the gas (rare).
I think i feel that there is a very slight power loss but not a lot. Could be on my mind but the car feels slight heavy. It does not feel sluggish tho or unrefined.
Fuel economy from computer I see that it is the same or even slightly less? but not much. I still have some gas left (I worked from home Monday and Today) so its looking pretty good.
Thats my experiment. It would be good to see/ask the 2nd gen people. Maybe some of them have a longer test on this or maybe even the ones that are running 87 for years can tell us if they run into any problems relating to putting regular vs premium.

 

Being an engineer myself I will say, The emissions system on the IS350 was not designed to run on regular fuel. Great example, The 3.5 V6 270hp in the Toyota Rav4's had a problem where water vapor would pool at the bottom of the Catalytic converters and rust out the bottom of the units causing a hole. The exhaust for the Rav4's are around $1500 and were covered under warranty with stipulations. Take a guess what caused the issue, you guessed it, people not running premium fuel in the engine. If you get rid of cars every 2 years then it will just be the next persons problem but if you keep the car 5 or 6 years your not doing yourself any favors by cheaping out at the pump.

 

Ok.... I had a 2007 RAV4 with that sweet V6 engine. The rav4 requires regular gas on all models and trim levels or are you saying that it was designed to run Premium but they used it on the RAV4 ??
Also, my Rav4 qualified for that rust in the muffler section. We bought it new and after 4 years there was alot of rust in the muffler and sounded bad. Toyota replaced it under warranty and we drove it for 7 more years and never had an issue with muffler (altho maybe was a little rusty... i never checked).

 

I also have the 2007 Rav4 and they replaced everything from the manifold back due to all the rust. Service advisor said they were told from Toyota to not run regular in the Rav4 with the 3.5 V6 due to the water vapor build up in the exhaust from regular fuel. mine was replaced in 2011 under warranty and we have been running 93 in it ever since and no signs of rust or excess water. 93 octane and Mobil 1 every 5k miles and the Rav still runs like a tank.

 

you know I have never heard this to run Premium on the Toyota RAV4 V6. Was there an official letter from Toyota??? cause this would be a huge problem. Do you know what it would have done to their sales if there was a recall and toyota officially telling people to use Premium on their Rav4 V6? i used to be at the toyota rav4 forums as well and i never came across this.

 

My sister worked at a Honda/Toyota dealer as a service advisor and was the one who told me. If I remember they covered it under the 8 year emissions warranty one time and informed you of the corrective issue. The service manager even said "This ones on us and the next ones on you" and don't run cheap gas in it. PA gets the ethanol blend in the winter but not in the 92 or higher octane. So the salt kills the car from the outside and the gas kills it from the inside.

 

Interesting. They never told me that but its something i will have to read more on.
Thanks.

 

Where did you hear that? (reference please) I buy premium fuel in PA fairly regularly (my sister lives there), and have never seen anything about this on the pumps.

 

You can Google it, I think there are only 7 states that do the blend and its never in the 92 or 93. The stations around Pittsburgh always put a sign on the pumps stating there is an ethanol blend. I always make sure when I winterize the Cub Cadet and lawn equipment that I don't use it.

http://fuel-testers.com/state_guide_ethanol_laws.html