smiley02190

has anyone tried regular gas on there mdx and if so what are the pros and cons, if any

JDLMDX

Going to regular gas will reduce power output under high engine stress applications (rapid acceleration, up hill, etc.)

Octane in your fuel raises the temperature at which the fuel detonates, or explodes. When the explosion occurs, it is before top-dead-center (TDC) and is called knocking or pinging. In ideal combustion, the fuel air mixture burns at a controlled (all be it VERY fast) rate with a subsonic flame front when ignited by the spark plug on or about top dead center (depending on the design of the engine). In detonation, the high compression of the engine causes the fuel-air mixture to explode with a supersonic wave front well before TDC, driving the piston in the wrong direction.

If you recall way back to high school or college chemistry, as you pressurize a gas, or in this case a fuel air mixture, the temperature rises proprtionally to the pressure (anyone remember p1v1/t1=p2v2/t2 ?). In a high compression engine, you need the higher detonation temperature of higher octane fuel.

The MDX, as with all modern high compression Honda engines, has a knock sensor to determine if detonation is taking place. If the sensor detects this condition, it reduces the amount of fuel / air mixture delivered to the cylinder. Knock is very bad for the engine, and will shorten the life of the engine.

NorCalAcura

Every Acura on our lot runs 87 octane and I've never noticed any problems.

JDLMDX

If you re-read my post, I talk about how it will happen when you are really stressing the engine.

I would hoope you haven't seen any problems. You'd be running the car at the high end of the engine output - not a nice thing to do to a car you're trying to sell, especially since it's not broken in yet.

I've detected the occurance on my 2000 TL when my wife put 87 octane in the tank and I was accelerating (had it floored) going up a steep hill on I-71.

NorCalAcura

As I've said... never experienced it. New and pre-owned Acuras including NSX.

Like I'm not going to drive a used NSX hard to make sure it's working 'right.' It's a tough job sometimes.

onlywayisup2000

If you are worried about gas prices, put 87, then an octane booster...might be cheaper...


also, i've always wondered the reason why Acura says premium fuel and Honda says regular unleaded...aren't they basically the same engine?

NorCalAcura

If you read the fine print on octane boosters you'll see that, when added to a 10-12 gallon gas tank, your octaine goes up perhaps 1 overall. At this rate you'd spend more on octane booster than you would just putting in the higher octane gas to begin with.

mickey513

That's because you guys never keep each Acura for long.....

NorCalAcura

We've had too many CLs on our lot for about a year and a TSX 6MT since November. So, you're not entirely correct.

mickey513

And how many miles go on these cars while they are on your lot? I'm pretty sure it's no where near what the average or evan a fraction of what a average person drives. You won't feel the long term affect of putting 87 octane from cars on a sale, which are what, driven like 10 miles on a test drive compare to one used for a daily driving.