I just bought my 2nd Lexus GS. My first, a 2001 GS300, which I put 120k miles on with very little problems, I ran regular unleaded in all the time. Manual and factory suggested premium. I said no after much research. Now, I have a new GS350 with the new 303HP engine and again, factory, manual and dealership recommend premium unleaded.

Do I REALLY need premium unleaded and do I risk damaging the car if I don't use it?

Thanks for the advice.

Cheers!

JV

This has been discussed at great length on many different threads if you run a search... You'll be fine using regular.. but you will lose performance and probably would get worse fuel economy than if you had just gone with premium gas... the ecu retards the timing to accommodate lower octane fuels but you spend the money on a lexus.. why cheap out now... just play it safe and use 91+ octane...

Thanks. Did the search and found a lot of information. Appreciate the info.

JV

Direct injection engines tends to built up with carbon in areas that a port fuel injection usually doesnt. That and the fact that the GS350's engine has a pretty high compression ratio, I would use a high octane gas that has superior detergent in it such as Shell V-power.

I have 3 luxury cars (2 Lexus and Benz), all of them recommend (not required) premium gas and I have only used regular unleaded gasoline. It has worked just fine. Save your money (it does matter in today's gas price).

And you can use Kmart motor oil in the Benz and it will still run, but I would not recommand it.

You can drink 10$ Whiskey or 300$ Whiskey. Why pay more if both going to make you drunk?! Answer: Your HEALTH and Hangover in a mourning! ( it this case - health of your car an components).

I just filled up on the way home tonight.
I paid $2.95/g. for 93 octane and pumped 15.35 gallons giving me a total of $45.28.
I noticed that the 87 octane was $2.79/g, so had I used that my total would have been $42.83

This gives me a difference of $2.45 which is basically the cost of a cup of coffee. My piece of mind is worth that.
I fill up on average about once every 5-6 days, so over the course of a year filling up with 93 octane cost me ~$165 more than if I had filled up with 87 octane. Hardly even worth posting about.

steviej

i agree its not worth the risk of getting a problem in your engine or trans even if there is a 1% chance a couple bucks still is not worth it, your driving a lexus