archerIII

RX300, 2000 Original Owner Purchased as Toyota Employee 138,000 miles 2 serious accidents Problems/Repairs: 2 A/F Sensors-replaced myself, I have Auterra Dyno-scan on my laptop for OBDII scans Power Antenna Mast-replaced myself Leaking rear main seal (vanished after engine de-sludging treatment, not sure why but happy anyway because it saved me $1000) Drivers side door latch assembly(water penetration?)-replaced myself $318 without tax 2 batteries, only good for about 4 or 5 years, I guess this isn't necessarily a problem but did have a Ford truck that lasted 9 years. Rear High Stop Tail lamp socket First brake job was rears at 65K Miles Second brake job was fronts at 74K Miles Third ..... 108K Miles? The original brakes were by far the best. Other annoyances: Accessory belt adjustment/squealing Engine noise (clacking),tappet or fuel injector at right rear of engine??? Strut bushing noise Idle vibration when in drive, often shift into neutral at stop lights

I am of the camp that uses Premium fuel in my RX300. I don't think that Lexus would recommend it if there wasn't a reason and I doubt there is a conspiracy with the oil companies. Recommending Premium can actually turn off a lot of customers. Who wants to spend an extra 30+ cents a gallon? My opinion goes back to my first Toyota V6 in a 1995 Camry. It did not like Regular Fuel, period. It hesitated and stuttered without Premium. It took me a while to figure this out since I did not initially read the manual. If you are experiencing problems I suspect you have a heavy foot as I do. Is that to say that a Mid Grade would not work? You'll just have to try it, and also try different brands. There are a lot of variables; season and weather,altitude, driving style, vehicle loading, fuel formulation, age or variations in the particular vehicle, etc..... All of these variables conspire to create a internal cylinder pressure and temperature that could cause detonation with a particular octane of fuel.