car recommends premium so why does it get the bes

[hypervish]

Originally Posted By: lexus114
Originally Posted By: hypervish
I run 93 in my RX as well, it too calls for 91 or higher.

I haven't calculated the mpg on anything lower than 91, but I definitely feel a loss of power on the butt dyno when running regular. Throttle is much more responsive on higher octane!



I see your using Quaker State Ultimate Durability 0W-20? Mine is burning a little on Pennzoil Ultra 5W-20. I smell it in the morning, and the tailpipe has a slight burnt oil residue in it. But I havent had to add any yet.


I did run Quaker State Ultimate Durability 0W-20 for one OCI. I just recently went back to Pennzoil Platinum 5w30.

I ran it for about 4,500 miles. Didn't consume any measurable amount of oil, according to dipstick.

I went back to the PP mostly because of the higher temps during the summer. I will likely be running Pennzoil Platinum 5w30 from here on out. Except for that one run of Quaker State Ultimate Durability 0W-20, I'd been running PP almost exclusively.

The only reason I went to the 20 weight was due to my 1 mile commute. I was hoping the 20 weight would warm up faster. Now that my commute is back to 40 miles, I have no need for the 20 weight.

I digress.

 

[lexus114]

Originally Posted By: hypervish
Originally Posted By: lexus114
Originally Posted By: hypervish
I run 93 in my RX as well, it too calls for 91 or higher.

I haven't calculated the mpg on anything lower than 91, but I definitely feel a loss of power on the butt dyno when running regular. Throttle is much more responsive on higher octane!



I see your using Quaker State Ultimate Durability 0W-20? Mine is burning a little on Pennzoil Ultra 5W-20. I smell it in the morning, and the tailpipe has a slight burnt oil residue in it. But I havent had to add any yet.


I did run Quaker State Ultimate Durability 0W-20 for one OCI. I just recently went back to Pennzoil Platinum 5w30.

I ran it for about 4,500 miles. Didn't consume any measurable amount of oil, according to dipstick.

I went back to the PP mostly because of the higher temps during the summer. I will likely be running Pennzoil Platinum 5w30 from here on out. Except for that one run of Quaker State Ultimate Durability 0W-20, I'd been running PP almost exclusively.

The only reason I went to the 20 weight was due to my 1 mile commute. I was hoping the 20 weight would warm up faster. Now that my commute is back to 40 miles, I have no need for the 20 weight.

I digress.



Got it,thanks.

 

[Cujet]

Originally Posted By: eljefino
Maybe 89 has no ethanol and 93 has 10%.


That would be my guess too.

However, sometimes combustion is more efficient with lower octane, under light loads.

My 98 F150 would ping like crazy on regular. But did return better MPG's on regular. Of course, now that I think about it, I would purchase regular on easy highway trips and avoid heavy throttle use.

 

[lexus114]

Originally Posted By: Cujet
Originally Posted By: eljefino
Maybe 89 has no ethanol and 93 has 10%.


That would be my guess too.

However, sometimes combustion is more efficient with lower octane, under light loads.

My 98 F150 would ping like crazy on regular. But did return better MPG's on regular. Of course, now that I think about it, I would purchase regular on easy highway trips and avoid heavy throttle use.




Well I was told when I used to work in the automotive field, that you get your best mpg`s at a light spark ping. (under load)