Regular Or Premium Unleaded Fuel?

[Dingpao]

Lexus recommends Premium (91 octate) fuel for my "new to me" 2000 GS300. Anyone tried using Regular (87 octane) or mid-grade (89 octane)? What, besides pinging could I expect from using the lower prices and lower octane grade?

I have not seen any posts on this topic before and would appreciate some tecnical as well as non-tech replys.

Thnks.

I have a 2003 Lexus IS300 and tried putting regular fuel in it and it would NOT start! i would recomend the good stuff..

[RX350lover]

I have used both Premium (91) and regular (87) in another brand of luxury cars (non-turbo) for more than a decade. My observation is that optimum performance of the engine is achieved using Premium, but the car will run just fine on regular. I cannot explain why, but on the highway, I got an improvement of 2-4 mpg while using Premium. In the city I did not observe a significant improvement.

Different brands of fuel often use the same suppliers, so identical fuel. Fuel with 10% ethanol means a reduced mpg as ethanol doesn't burn as efficiently.

I don't believe it can happen, but if you are concerned about making your engine dirty with regular (87) fuel, then buy a bottle of 'complete fuel system cleaner' (STP at Walmart) and add it to your tank a few weeks before going for an oil change.

Higher octane gasoline facilitates explosion and therefore provides better acceleration. It doesn't do much else.

I believe that all cars (non-turbo) will run just fine on regular. But the car manufacturer might want you to use Premium as it makes their cars perform better, though not vital to your engine.

[LEX-SV]

Lexus-recommended fuel is my preference, I consistently use Chevron premium in my IS350.

[reyoasian]

Not sure about other cars but the IS250 tends to have a carbon buildup issue which is better off with 91

But generally speaking, you just dumb down your knock-off sensor to accept regular fuel which in short run results in lower mileage and decreased power, but not sure about long run

[LEX-SV]

Not sure about other cars but the IS250 tends to have a carbon buildup issue which is better off with 91

Why (curious)? The top tier brands have same detergent levels in both regular and premium grades of gasoline. Regardless I think premium gas is recommended for both IS250 and IS350 engines.

[Whisperss]

I run premium (91 octane) in my 06 IS 350 and have no issues with motor ping or anything else.

[pj8708]

Lexus recommends Premium (91 octate) fuel for my "new to me" 2000 GS300. Anyone tried using Regular (87 octane) or mid-grade (89 octane)? What, besides pinging could I expect from using the lower prices and lower octane grade?

I have not seen any posts on this topic before and would appreciate some tecnical as well as non-tech replys.

Thnks.

Go to the top of the page and Google "wich gas to use". Should give you enough to read on the topic for a lazy evening.

Paul

[VBdenny]

Never considered using anything but premium. Besides, with gasoline this cheap, we better burn it up while we still can. Many stations are beginning to sell gasoline without the alcohol.

[Bykfixer]

Fast forward 6.25 years and $20 got me 6.05 gallons if 93 octane. Gyah! 

5 bucks aint gas money no more. Used to be mid grade was 10 cents more than regular, premium 10 cents a gallon higher them mid grade, but Saturday in my town regular was $2.79 and premium $3.29. Yet at one point premium was a dollar more than regular. 

The Rush song Red Barchetta was bouncing around my head on the ride home as I pondered a day when driving a petrol burning car will be a novelty. 

 

[Flyvfr2]

Use what the manufacturer recommends, as they do a lot of R&D on this.