It has never occurred to me before, but are we killing our engine by using the lowest gas rating (89) ? (Cheapest gas.)

Specifically, the Volvo 2.5 T, and Saab 2.0 T H.O.

 

Surely the VVT system is supposed to adjust the engines settings automatically to maintain the appropriate fuel/air/temp etc ratios for combustion within the required range to perform correctly.
Below the recommended range then yes, you may be right.

 

So, is that a "fancy" way of saying we're OK ? The Volvo is an '05 (V50) and the Saab is an '02 (9-3 SE) I'm not sure if these two are equipped with the VVT. Thanks!

 

see the link below from wikipedia
Trionic - Wikipedia, the free encyclopedia

According to that saab 9-3 from 2000 have a 'Trionic 5 engine management system'
The V50 has VVT.

Reading the blurb it would appear that their system (Saab) whilst different, performs a fairly similar function overall to ensure optimum engine performance.

 

Thanks a million!