Greetings all, I have a 2013 RDX. I live in the southeast of U.S. where they put ethanol in most gas. Is it better to buy the Acura recommended 90 or higher octane with ethanol in it or go with the lower 87 octane that has no ethanol in it? I've always heard better to have no ethanol as the engine will perform better, however, Acura recommends the high octane gas.

 

Do you know if mid-grade is free of ethanol? That would seem to be the lesser of two evils of lower octane 100% gas compared to higher octane with 10% ethanol+mpg hit.

 

I will ONLY put in 91 / premium grade.

 

Butt Butt, what if your state offered Non-ethonol 93 octane?

because we are not arguing which fuel is recommended but which fuel burns at the optimum time

 

meh...I'm in Canada...got no non ethanol choices

 

Here in the states, where the political agenda is $$$, they push corn, which lowers the ability of gas to burn efficiently.


so, it's pretty much a toss-up. I know where ever I go to fill up, I will always have ethonol in my fuel. so, 93 octane is as best as I can get.

 

Here in GA/SC the only non-ethanol choice we have is 87 octane.

 

^yeah, i wouldnt use it.

 

Don't the pumps do in situ mixing of the high and low octane fuels to get midgrade?

So running the mid would still result in an percentage of cornahol, and my maths say it would be roughly 50% of what would be present in the high oc.

I'm not sure my inputs helped anything...

EDIT: except to say that running mid grade might be the best of both worlds... or the worst... Not sure.

 

^going off what cu2wagon said; I dont think the corn lowers the efficiency of the fuel that much to where it is equal to pure 89 octane

 

Avoid ethanol at all costs.

 

All of our fuel has it. It cannot be avoided where I live.

 

What? Where? Across Alberta, all 91 is ethanol free.

87, 89 and 94 all have ethanol here.

 

You are correct, however, I don't exactly know where the mixing occurs.

Here, regular (87) has 10% ethanol

Premium (91) has 0% ethanol

Mid grade (89) is just a 50/50 mix of the above, and has 5% ethanol.

I believe the 94 we have here has 10% ethanol, also.

 

There, I corrected that for you. Other parts of Canada have choices. In most cases regular contains 10% E, mid grade 5% and premium 0%.

 

Let's not confuse octane and ethanol. In theory, ethanol has a higher octane rating than gasoline, but at the 10% where we are in the US, there is little noticeable difference in octane ratings. The energy content of ethanol is about two thirds that of gasoline, so your E10 should yield about 3% lower gas mileage. In real life testing however, the gas mileage hit has been much greater.

Some regions have also been doing E15...

 

Non ethanol recently became readily available around here, 91 octane only. I use it in both Acuras and my Vintage rides. More expensive, supposedly better for seals, gaskets, etc. in the old cars, small engines, etc.

 

I use super premium 91 Octane containing zero ethanol. It is about 10% more expensive than regular gas but also gives me better mileage and is better for my engine health and performance so the price difference is negligible. I've been getting a range of 600 - 700 km on one tank of fuel. Varies depending on how long a stretch I go with less stop and go traffic and how fast I'm going. Also, I've been taking it easy on the gas pedal until I break in the engine.

 

Thanks everyone. It looks like there is no solid answer but to seek out non-ethanol gas when you can and hope it is high octane.

 

The solid answer is go for 91 Octane or higher with no ethanol (ethanol may not be good for the engine).

 

Shell highest grade Vpower (91 Octane) is ethanol free, here in Ontario.

 

Yep and Canadian Tire gas bars 91 Octane or Costco 91 Octane along with a few others like Shell and Petro Canada