xenocide

I've noticed that when idle at a stop light for example the needle on the tach seems to wobble a little and also when im cruising at a constant speed not using cruise control the engine seems to drone a little like its not receiving enough fuel and there is a slight vibration in the gas pedal. does not happen when CC is engaged as far as I can tell. Anything I should be worried about?

rmurad38

This engine seems to have a slightly rough and uneven idle, but I found that running better than 87 octane helps. As for a drone or unevenness while crusing, i havent really noticed that, might be questionalbe gas,, perhaps try a different brand or the next step up in octane?

xenocide

The drone thing almost feels like when you shift too soon in a manual. That kind of feeling.
I'll try higher octane next time I fill up.
Thanks.

hogasswild

I've noticed that 93 makes the engine run much more silky, plus butt dyno says there's more power.

xenocide

I filled her up with midgrade and i averaged 33 miles per gallon on my way home instead of the avg 28. Peak mpgs was 42. hasnt improved idle needle wobble or the feeling like its not getting enough fuel.

LostBoyz

the v6 isn't setup for anything other than 87, so no you don't get any more power like the v8 does. You also wouldn't get better fuel economy because higher octane fuel actually has less potential energy storage, it has a higher resistance to detonation.

hogasswild

This has been discussed ad naseum. Due to the advanced variable timing, you do in fact increase power and MPGs. I have been tracking my fuel economy on fueleconomy.gov and can tell you, I get 1-2 MPG higher on 93 octane.

LostBoyz

I would believe that if you were running a 93 tune, but stock there is no system for octane detection on the v6. The v8 has it and yes you get more power and better fuel economy from premium fuel because it was designed for it.

6+6 Stang

HEY finally a thread where maybe I can verify the truth.....as I had a '10 GT Lostboyz, you are right...93 on my v6 only made my wallet lighter, cuz my v6 is stock, 93 made the GT little more peppy when had stock tune in it, even when had a 87 performance tune in the GT 93 did not help it.

Radioguy

Actually, the ECU in the 2011 Mustang is much more advanced then the model used in the 2010 Mustang. This article is worth a complete read:
http://www.musclemustangfastfords.co...v6_engine.html

However, in part it says:
"The powertrain ECU has been upgraded with a very aggressive deceleration cylinder shutoff for fuel economy, coupled with very rapid tip-in for street performance. On the flip side, the ECU has been reprogrammed with adaptive-knock spark control. If the two knock sensors embedded in the cylinder block don't hear knocking, the ECU will keep advancing the spark until it does.

What this means in performance terms is that, if the owner uses premium or race gas on weekends, the engine should make considerably more power and torque than the numbers quoted here, which are the product of standard SAE dynamometer laboratory testing procedures and not real-world driving."

So, yes the V6 engine will perform differently on 91/93 octane fuel then on 87 octane fuel.