Does anyone own the 4th generation SH-AWD 3.7 model and use 87 octane? If so, have you experienced any abnormalities at all? Emission/check engine light? or anything else?

 

No, you won't get a CEL just from using lower octane. I've done it before on lots of cars that need 93 octane. Sometimes it was because I was on a road trip and the area I was in only had 87 oct. Or sometimes, I ran the car the entire time in 87 because I'm ruthless.

You'll get more knock count and worse MPG.

Eventually, in a long time, you might see some component/sensor/engine damage or wear associated with it. And at that time, you'll see a CEL.

Or maybe nothing will happen. Try it out.

Your owner's manual pretty much states what I've just said too. In the short term, just lower MPG and power. In the long term...potential engine damage.

If its a game of economics, just total up how much money you'll save at the pump. Subtract the lower MPG and potential damage from your total "at the pump" savings. Easy peasy.

 

What car do you have? and for long did you use 87 octane? months? weeks? or was it just couple of times?

My car requires high octane but I"ve been using 87 for a year. The other day CEL came on but is gone after a few days. I'm wondering if I should switch to 93

 

06 TSX - long term 87 octane use
11 TSX - long term 87 octane use

Nothing happened for years.

2012 TL SH - used 87 octane a couple times when needed
Same for my S2000 and my wife's S2000. Sometimes you find yourself out in rural areas that only have 85 or 87 octane choices.


Find out why your CEL is coming on before you do anything.

 

When I first got my 2014 TL 3.5 I was putting Sunoco 93 gas since it closest to me and I was getting 20 mpg I do 80% city 20% Highway
Then I started filling with shell 93 and my gas mileage went down I was getting 17 sometimes 16 mpg same drive and same route
I just switched back to Sunoco 93 again and gas mileage went back to 20 mpg
I don’t understand it since shell 93 V-power is supposed to be one of the best gas to get 🤷‍♂️
I only had the car 2 years and I haven’t tried any other Gas except them 2 since they’re the closest tier 1 gas stations near me

 

3.7 Engine + 87 octane = world of hurt

 

I will admit to trying 87 for a short period of time as I go easy on my car. I switched back to 91 because I go up a highway with an 8% grade and could detect a slight knock going uphill in 5th or 6th gear. These cars likes the good stuff