Has anyone experimented with using a higher octane gas...like 93 vs. 87. I find the vehicle underpowered, especially at high speeds lacking passing power. I have filled two tanks with 93 octane and this seems to help a little. Thoughts and or suggestions...... I had the highlander and that screwed in comparison. Same engine, lighter vehicle, one more gear on the tran (at least the model I had 2014).