I found a used 2013 rdx to purchase. the seller told me that it was nice that it ran on regular fuel not premium!!!!! He has owned it two years. Would there be long term damage running it on 89 rather than 91 premium?

 

I would say no damage. I base this on that there is a knock sensor that will detect cheap gasoline and prevent the engine from knocking by retarding the timing. Yes, the car is designed for premium, but regular will not hurt it. It just won't run at peak performance.

 

Ran mine on 89 for about 3 months until going back to premium. Woudln't say there was any damage, but car definitely ran smoother on premium.

 

Running on 87 no problems. The knock sensors do their job as needed. Fuel door says tells me "Premium Fuel Recommended" rather than Premium Fuel Only or Required. I've tested strictly on fuel economy on several tanks of premium vs regular. Premium wasn't getting me anything so we switched to the cheap stuff.

 

The manual for my 2014 RDX specifically says that running fuel with an octane level *below* 87 can cause damage...

Regular (87 octane) does not appear to do so.


RFT!!!
Dave Kelsen
--
The one thing I think I know is that I'm uncertain... but I'm not sure.

 

Non Ethanol gas is better for your engine. I run 87, non ethanol in my 2016 - runs great, I've used the 91 non ethanol - but wasn't seeing anything in terms of performance gains or fuel economy, so I switched to the 87 octane.

PureGas is the app if you need it to find a facility that carries non ethanol gas. Hope that helps!

Kendal

 

Acura recommends 91 octane, however its not required, which means that 87 and 89 are perfectly acceptable. You will see slightly less power and slightly less mileage running 87 octane.