do I need to put premium gas in my lexus or can I use the cheaper (choke) stuff and not impact the mpg
The owner's manual will say that it must have high octane or that it may use regular but should use high octane. The parts the leave out are:
If it needs high octane, using regular can damage the engine.
If it should use high octane then it has a system to sense the low octane and to make adjustments to the car that will protect the engine. However the adjustments will result in lower mileage (reducing or wiping out any economic advantage) and will reduce the power, defeating the reason most people buy cars that require high octane.
Using high octane in a car that does not recommend it very very seldom causes damage but cost you more and offer no advantage.
Premium is cheaper now in relation to regular than the past at only 6% more. Back in 1995 it was 17% more!
I’ll echo Mr. Meehan’s post.
There’s 3 kinds of cars; 1 that REQUIRES high octane, 1 that recommends high octane, last kind that runs on low octane. If your car requires or recommends high octane, USE IT. You’ll find this information, as well as a lot of other useful facts and tips for your car, in a book in that little storage compartment called the glovebox.
You bought a premium car, why cheap out on fuel?