[335M_PR]

One of the biggest fuel retailers in the island started providing an 87 octane regular with 10% ethanol mixed in. We only have 91 octane premium readily available. A handful of stations have 93, although it is priced extremely high. Would there be any benefit in running this 10% ethanol regular rather than the 91 premium? Would this regular blend be comparable to an E90? Thanks!

[Ænema]

Ummm.... Just run the 93 octane. Don't run 91 if you can help it and avoid anything less like it's the plague.

[335M_PR]

I would be running 93 if it would be readily available. However, this is not the case. I've been running 91 without issues for the past 1.5 years.

On this 87 octane regular with 10% ethanol, logic would tell me that they're using lower octane gasoline and using the 10% ethanol to increase its octane to 87. However, I'm not sure if this is the case. What if they're using normal 87 regular and then adding the 10% ethanol. If that's the case there would certainly be a increase in octane and the car would benefit from it. I'll try it out on my next fillup. Any feedback is welcomed...

[ErvGotti]

Originally Posted by 335M_PR

I would be running 93 if it would be readily available. However, this is not the case. I've been running 91 without issues for the past 1.5 years.

On this 87 octane regular with 10% ethanol, logic would tell me that they're using lower octane gasoline and using the 10% ethanol to increase its octane to 87. However, I'm not sure if this is the case. What if they're using normal 87 regular and then adding the 10% ethanol. If that's the case there would certainly be a increase in octane and the car would benefit from it. I'll try it out on my next fillup. Any feedback is welcomed...

No that is the case. If it's branded as 87 octane it's 87 octane plain and simple. Meaning with all of it's components combined including the ethanol it's 87 octane. Stick with 91, even pure 87 blended with E85 to increase it to 10% ethanol will only raise the octane to 89.3.

[MDORPHN]

Pump gas with 10% ethanol is E10, not E90.

Agree with other posters about running the 91 or 93 octane.

Neil

[335M_PR]

Figured. Thanks for the feedback.