Imz-fe engine compression ratio

[Skyguy]

Can anyone tell me the compression ratio on a V6 1MZ-FE engine istalled in '98 Camry LE. I haven't been able to find it in any of the info I have including the Toyota shop manuals. The owners manual recomends using premium gas for "improved engine performance" and I'm curious to know. Thanks

[sidler73]

In the Solara that engine is 10.5:1
In the Camry 9.6:1 regular gas will actually run better.

Running premium, slows down the burn rate of the fuel. Octane does not actually exist....it is simply a calculation of what rate your fuel will burn at based on the chemical composition (additives) combination in the fuel. The higher the octane rating the slower fuel will burn or more pressure it can handle. There are only a handful of cars (production) on the street that require "premium" fuel. Your car (in stock trim) will run better and make more HP on regular, because the compression ratio combined with the 87 octane fuel rating "match" .
A higher octane rating in a low compression engine causes partially unused fuel to exit the engine, over time this will coat items like the 'O2 sensor.
Hope this helps.

[Skyguy]

Sidler,
Thanks very much for your very helpful and informative reply.
Skyguy