[instalher]

hey guys I have a question on octane.. I just bought a 2017 x1msport.. now I am filling up with 3/4 of 87 octane and 1/4 94 octane, this saves me a bit of money over a full fill up of 91octane, Can anyone see any potential issues with doing this on the b48 engine?? I use Costco for 87 octane and husky for 94 gas.

[Skyline2.0]

Originally Posted by instalher

hey guys I have a question on octane.. I just bought a 2017 x1msport.. now I am filling up with 3/4 of 87 octane and 1/4 94 octane, this saves me a bit of money over a full fill up of 91octane, Can anyone see any potential issues with doing this on the b48 engine?? I use Costco for 87 octane and husky for 94 gas.

No issue mechanically to mix octane. I've been doing the same with 89 and 93 (no 91 near me). I usually refill at the half tank mark and switch between 89 and 93, depending on what I filled last, to get an overall 91 octane rating.

But, the financial savings may be negated if you need to go out of your way to one of the gas stations. Luckily I go to the same gas station that's a block away, so I dont use more gas per trip.

[Beagler]

We have Shell Nitro unleaded here. I find it does make a difference in performance being 99 Ron. I also think it slightly improves mpg and so helps offset extra cost.

[kavatski]

You can mix different octane fuels if that’s really what you want to do, but make sure you’re getting the right mix. You’d have to do a 50:50 split between 87 and 94 to get even a 90.5 average, so at your 75:25 you’re getting more like 89. That’s the minimum for the engine so technically it should be fine, but are the savings really worth it over just filling up with 91?

[ttimbo]

In my experience (Australia uses RON for octane measurement), using 95 RON (BMW's minimum) only saves money at the fuel pump; consumption is higher. So, I've standardised on 98RON for better power and economy.

[Skyline2.0]

Originally Posted by ttimbo

In my experience (Australia uses RON for octane measurement), using 95 RON (BMW's minimum) only saves money at the fuel pump; consumption is higher. So, I've standardised on 98RON for better power and economy.

Good point, ttimbo. I see, on average, about 20 to 40 miles per tank more when using 91 (mixing octane) or 93 on the rare occasio vs 89, based on my miles to empty meter in the dash. Using the bare minimum (89 octane) or less will likely negatively affect fuel economy, engine knock prevention and performance. On the flip side, anything higher than the recommended 91 wont result in better figures.

[instalher]

hummm I will due some more long drive tests with 89 vs 91 vs 93..