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InlineVorex InlineVorex is offline
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Default My BMW 335i issues completely resolved using 95 octane! Runs rough on 98 octane - 09-22-2021, 05:01 AM

Hi guys

I made a thread here couple of weeks ago in regards to my 335i running completely rough. It had rough idle, low boost, pulling timing and sounded like the engine was running on 4 cylinders.

I have been using the best 98 I can find. 6 months my car has been running like an absolute dog!

Until I decided to fill up with 95 octane and low and behold my car completely transformed!! After a couple kilometres my engine note started sounding like n54. I gained back all my bottom end torque and my car was running closer to what it used to. I ran the tank low and refilled with a full tank of 95 octane and by this point my car stated running absolutely amazing! There's no way 95 octane should be running better than 98 right?

I decided to test this by running the car on 95 for an entire week and the car was back to the n54 I fell in love with. I then decided to fill up again with 98 at BP ultimate and after a couple of kilometres my car started backfiring, pulling boost and running like an absolute dog!

Can anyone explain why my car is running so rough on 98 octane!? And it's not just one petrol station! I have used them all with the same results! My car just runs like rubbish on high 98 octane! ��

Would this be a spark plug issue? Please any help would be appreciated! Because I would like to start modding and tuning Ruth MHD soon but I know 98 is required and I'm scared to use that octane of fuel now!
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InlineVorex InlineVorex is offline
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Default 09-22-2021, 09:18 PM

Any help guys? ��
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Steve @ BMS/Fuel-It! Steve @ BMS/Fuel-It! is offline
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Default 09-23-2021, 07:11 AM

Without a log, there's not much information available so you're not going to get much feedback.

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