Will using Premium gas in the HS increase gas mileage or not worth paying the extra?

 

Everything I've ever read said that using anything above the grade recommended by the manufacturer was a waste of money. Having said that, on older cars with carbon build-up, it's sometimes necessary to go up in grade to reduce knocking/pinging.

 

The oil company will appreciate the extra revenue if you use premium. As sublexus said, stick with what Lexus recommends (i.e., regular gas).

 

And the Lexus sales literature both on the internet and that which was available at the show room both acknowledged that indeed the car will have more power and better gas millage if 91 octane gasoline or higher is used. The car has sensors that can correct ignition timing for octanes as low as 87 but mileage and power will be effected. As an opinion it seems the lower octane gas will give better miles/dollar because the increase in mileage using higher octanes does not seem to provide higher mileage proportional to the increase in cost. But I don't know. I always use premium because (I think) I have better acceleration.

 

Maybe that's true for other Toyota models that are designed to run on premium, but for a 2.4 liter Atkinson cycle engine, like in the HS, it's only needs regular 87 and, if I remember right, will not adjust the timing as other non-Atkinson cycle engines do.

My advise is to save the money. Premium in a hybrid is kind of pointless because you get no gain and the cost difference between Regular and Premium negate the reason to own a hybrid.

Sadly, most every other new car out there seems to HAVE to run on premium. Something most new car buyers never take into account for the overall cost of ownership when they plunk down the money.

 

Split the difference and go midgrade 89

 

Through 3 takes of regular I am average 34 mpg per. I may try a tank of premium to see if there is a difference...

(Just for kicks)