View Poll Results: What octane do you put in your 328i? | |||
87 octane | 2 | 2.25% | |
89 octane | 15 | 16.85% | |
91 octane | 72 | 80.90% | |
Voters: 89. You may not vote on this poll |
Post Reply |
|
Thread Tools | Search this Thread |
09-01-2012, 12:44 PM | #23 |
Yup
104
Rep 699
Posts |
93
__________________
Oh hello
|
Appreciate
0
|
09-05-2012, 09:47 PM | #24 | |
Major General
890
Rep 7,047
Posts |
Quote:
BMW doesn't "recommend" 89 US octane fuel. That is a minimum recommended octane rating, meaning the engine will run ok with that fuel grade. You can even run 87 octane in your turbo, the knock sensors will trigger and the ECU will alter tuning to compensate. The best performance required rating is 91. Will 93 be better? That depends on whether the engine is tuned to achieve higher output that requires 93. The one benefit to using 93 is that it gives a greater "head room" to knock occurring in the first place. You may not get more power with 93, but it could help reduce the tendency for knock. The reason the engine can run that lower octane is because the engines have a knock sensor. With 87 or 89 octane the engine will fun just fine...until it encounters knock, which it will once you start increasing throttle input along with higher temps. Then, the ECU will start to retard timing until those knock events get under control. When timing gets retarded so does peak power production and efficiency. As you continue to drive the ECU will continue to advance timing again to get back to peak efficiency. If you're driving moderately, and the air temps are not too hot you can keep knock at bay for a while, until it rears it's head again. Then, the ECU will retard timing again to get it back under control, and the cycle repeats. The point is that the ECU will keep trying to get back to best efficiency and best power output, but if you don't give it the required fuel, then it can't get there and stay there. You may not notice a difference for a couple of reasons. One, the engine will run smoothly and fine even though it may be producing less power. If you're just driving around in daily driving and not using a lot of throttle, you'll likely not notice the reduced power, as you're not asking for more power. Knock tends to occur at high loads and greater throttle with high compression loads. Another reason could be that you're used to the reduced power so you don't notice it's gone. Still, the fact is that these turbocharged engines with rather high compression ratio's for turbo engines, REQUIRE higher octane fuel to run at their best. That can be measured on a dyno, no placebo recommended or required. There is a big misconception about octane. There are a good number of people who believe that their engines will perform better and give them more power, and even better MPG, simply by running high octane "premium" fuel. No, that not true. If an engine is designed to achieve it's peak power and best efficiency on 87 octane fuel, then running 91 or 93 octane will NOT give them more power nor better fuel economy. Those people are throwing their money away for no reason, other than their misunderstanding of fuel octane and their engines. That is not the case here with BMW's turbo engines, and high performance NA engines. There are many places on the web to get this kind of info. Here is one in particular that cites BMW and GM engineers. http://forum.roadfly.com/threads/126...ctane-gasoline Last edited by RPM90; 09-05-2012 at 11:05 PM.. |
|
Appreciate
0
|
09-06-2012, 07:56 PM | #25 | |
Captain
58
Rep 747
Posts |
Quote:
That being said, if I were to pick up a tune and run 91 octane, I'm sure I'd pick up a considerable amount of power. |
|
Appreciate
0
|
09-07-2012, 09:00 AM | #26 |
BMW 4 Life...
149
Rep 3,360
Posts |
So,
For a 335i, considering its and i6, should we use 91 or 93? I mostly go with 91 but at times kinda get stuck with 89... What's the best recommendation for a 335i?
__________________
MODS: *** / M Sport + Performance / Meisterschaft / Challenge / MORR / more to come! ***
|
Appreciate
0
|
09-07-2012, 01:04 PM | #27 |
Captain
58
Rep 747
Posts |
BMW recommends 91 octane for the 335i. Going above the recommended will not be beneficial, but I would not make a habit of going under either.
|
Appreciate
0
|
09-07-2012, 02:11 PM | #28 | |
BMW 4 Life...
149
Rep 3,360
Posts |
Quote:
I noticed a serious dip in my MPG everytime I use 89, so I guess I'll go back to 91...
__________________
MODS: *** / M Sport + Performance / Meisterschaft / Challenge / MORR / more to come! ***
|
|
Appreciate
0
|
10-06-2012, 08:22 PM | #31 | |
BMW 4 Life...
149
Rep 3,360
Posts |
Quote:
__________________
MODS: *** / M Sport + Performance / Meisterschaft / Challenge / MORR / more to come! ***
|
|
Appreciate
0
|
10-09-2012, 01:50 PM | #32 | |
First Lieutenant
38
Rep 387
Posts |
Quote:
|
|
Appreciate
0
|
10-10-2012, 11:06 PM | #33 |
1ST CLASS AWMSPORT
74
Rep 789
Posts
Drives: 13' 328 MSPORT
Join Date: Sep 2006
Location: South Fla
|
Always used. 93. Will neverchange. (unless Need it badly and out of 93. Then just enuf to get me to another station . ) lol
__________________
'13 328i MSport, AW, Black Dakota leather, Premium Pkg, xenons, ///M Perf, side skirts,Front Lip, Fully coded, CF roundels, Matt Black Grillz, Painted reflectors (front & rear) Smoked tail lights, Plazma l.E.D White PY27W front turn signal,trunk spoiler, Matt Black roof, 8K D1S HID,Custom Exhaust,!
Soon: JB4,DP,H&R sports,rear diff,! |
Appreciate
0
|
10-11-2012, 11:07 AM | #34 | ||
Private
7
Rep 88
Posts |
Quote:
__________________
2015 Macan S Sapphire Blue 20" SD Wheels Painted Black SD Kit Sport Black Chrome Exhaust
2012 BMW 328i Sapphire Black Blk Interior Premium Executive |
||
Appreciate
0
|
10-12-2012, 01:50 PM | #35 |
Captain
58
Rep 747
Posts |
Yesterday I filled up with 91 octane and I haven't really noticed any difference. I want to see if the cold start and idle will be quicker with 91 octane in addition to be faster.
But BMW using 91 octane for the dyno testing was news for me. Thanks for sharing the info. |
Appreciate
0
|
10-12-2012, 02:03 PM | #36 | |
Sarcasm free with all posts.
7
Rep 441
Posts |
Quote:
__________________
The best 2013 M sport is owned by me.
|
|
Appreciate
0
|
10-12-2012, 06:38 PM | #37 | |
Enlisted Member
0
Rep 34
Posts |
Quote:
|
|
Appreciate
0
|
10-13-2012, 03:21 PM | #39 | |
Captain
58
Rep 747
Posts |
Quote:
I'm half way through my tank of 91 and I do have to say that cold starts are quieter and it idles more smoothly... Maybe I'm converted back to using 91 octane permanently |
|
Appreciate
0
|
10-15-2012, 03:16 PM | #41 |
Sarcasm free with all posts.
7
Rep 441
Posts |
Precisely.
__________________
The best 2013 M sport is owned by me.
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|