BMWs do not require Premium fuel...Only recommended?

[Swift135]

Originally Posted by E82TT6

The motor will likely go into limp mode, or close the throttle, pull timing, and open the wastegates to retard knock.

I disagree; the spirokeet sprigometer will override the retard knockometer and that should probably fix the lameness mode!

[Oregon]

Since acquiring my very-first car, premium has been the elixir of choice. Heck, I add octane-booster for the V-8 in the Buick. Put the good-stuff in your Bimmer. Keep him happy.:wink:

[stso0000]

If you're really strapped for cash, why not fill up the tank with half 93, half 89? That gives you 91 octane gas.

ST

[Smokey]

Here's a link to a video of octane rating comparisons done by Fifth gear a while back-- I know the u.k's octane ratings are different from ours, but the results are helpful

[dorkdog]

Originally Posted by ryguy85

I always stick with premium even in a 128i. The lowest i would consider is 89, 87 probably just for emergency type situations if they ever occur. Even the NA 128i has a decently high compression and with regular gas im quite sure you would notice the change in performance when accelerating under a decent load.

Out of habit I filled my new-to-me 128i with regular a couple days ago. I really do feel a difference in performance; so much so that I am researching it here and reading this thread. The car is not as fun to drive with regular. Not nearly as fun. So much so I'd purge the tank if it were handy to do so. As it is, I refilled (topped off) from the halfway point with 93 so hopefully my car will feel better tomorrow

[jsmonet]

Originally Posted by mfratt

Well, to be fair, its more like $4.

12 gallons * ~10 cents/gal diff = $1.20 tops you're getting hit each fillup.

going 87 to 91/93? double it to 2.40.

Is this the first turbo car for some of you? the dynamics of a boosted motor go beyond simple things like retarding timing and upping afr to account for crap gas. have an especially hot day, especially bad traffic, a bit more heat soak in the IC than normal, you're inviting bad things and sacrificing performance and a bit of safety buffer in the combustion process to save a minuscule amount of money.

I'd be more likely to pull this with a lower CR NA motor where things aren't quite as... dynamic.

[flinchy]

holy thread ressurection batman!

only 98 RON in my 130. if you're going to spend this much on a car and half kill it with low grade fuel, you make me sad.

[Satalite]

Originally Posted by flinchy

holy thread ressurection batman!

only 98 RON in my 130. if you're going to spend this much on a car and half kill it with low grade fuel, you make me sad.

Its preference. BMW states a recommended grade of fuel for the sake of "performance" standards that BMW sets. These engines today are built so they can accept any octane level of fuel. The downside of going lower especially with sport cars is the lower performance and getting the necessary combustion that you need to make the engine efficient.

I usually run mid grade 89 in my 1'er as per recommended BMW. Haven't tried "premium" 93 yet as I only drive a 128. Don't see the reason unless I'm racing around the city...

For all the 87 octane haters..

[flinchy]

Originally Posted by Satalite

Its preference. BMW states a recommended grade of fuel for the sake of "performance" standards that BMW sets. These engines today are built so they can accept any octane level of fuel. The downside of going lower especially with sport cars is the lower performance and getting the necessary combustion that you need to make the engine efficient.

I usually run mid grade 89 in my 1'er as per recommended BMW. Haven't tried "premium" 93 yet as I only drive a 128. Don't see the reason unless I'm racing around the city...

For all the 87 octane haters..

it also states in the manual, that it will reduce power (don't think it states fuel economy though), and it reduces it by a LOT (both performance and fuel economy).. by using higher octane fuel it can run more advanced timing, and inject less fuel for the same power.. not only does the car retard timing for lower octane grades, it has to inject more fuel to cool charge temps (running slightly rich cools cylinder temps a lot)

you barely even want to run 91RON in a piece of crap econo car, let alone a (australian pricing) $70,000 highly strung car. i mean, you wouldn't even run that shit in a honda (their higher spec engines at least, you run 91 RON in a type-r or a H22 and you WILL destroy the engine), so why would you put it in your bmw??.. just because it has safety features so people don't put crap fuel in it and damage the engine, doesn't mean you should.

[RaihaX]

only 98 + meth for me

[chili555]

and it reduces it by a LOT

[Citation needed]

[Dackelone]

Originally Posted by backtoreality15

...And he started talking about BMWNA and some chemist doing a study, etc.
What are you guys' opinion this? Bunch of mumbo-jumbo?

SIMPLE... garbage in... garbage out!

I only use SuperPlus ( = Premium) gas. It probably also depends on your fuel brand... bc sometimes their premium fuels have more detergents and additive packages in them, that te regular and super (mid) grades do not get.

[BroDoze]

Originally Posted by plien69

In fact, probably the opposite is true. Cruising at highway speeds is not stressful for the engine at all. There's not a lot of load, lots of airflow for cooling, etc.

It's going around town, with it's many starts and stops, that puts more load on engines and calls for higher octane.

Highway's can be the MOST damaging with low-octane fuel. In high gear, like 5th or 6th, if you are climbing up a long hill, even with slight throttle, that kind of load is some of the worse load you can put on an engine. Lower gears you're much less likely to cause det.

[dry_heat]

Why would anyone drop down to a lower grade fuel when driving a $40,000+ car just to save a couple bucks per tank?

This completely eludes me. I've been putting 91 octane from trusted big name gas stations in every car I've ever owned, and I'd use 93 if I could. A few bucks a month is more than worth the cost in exchange for fewer worries about how your inferior gas could be hurting your engine or costing you power or fuel economy.


The way I see it, if my 1996 Honda Prelude VTEC wanted "premium fuel only," there's no reason not to put the same or better fuel into my 2009 twin-turbo BMW.

[RPM90]

It is "recommended" that you do not put your hand in a fire.
You're not "required" to not do it.
It is only a recommendation. You can do it if you like, there is no restriction on not doing it. But, then you have to deal with any consequences if you choose not to heed that recommendation.

[terrapen73]

Originally Posted by dry_heat

Why would anyone drop down to a lower grade fuel when driving a $40,000+ car just to save a couple bucks per tank?

This completely eludes me. I've been putting 91 octane from trusted big name gas stations in every car I've ever owned, and I'd use 93 if I could. A few bucks a month is more than worth the cost in exchange for fewer worries about how your inferior gas could be hurting your engine or costing you power or fuel economy.


The way I see it, if my 1996 Honda Prelude VTEC wanted "premium fuel only," there's no reason not to put the same or better fuel into my 2009 twin-turbo BMW.

Do you all not have 93 octane? I have not driven much out west and haven't paid attention to the octane available. Everywhere I normally travel on the east coast has 93, 91 or 89, and 87 octanes available. Some stations will have 100+ race gas available as well. These are normal gas stations, nothing special. Just curious how different things may be right here in the US even.

[P7X]

Is this really a thread....

[Tom K.]

Originally Posted by terrapen73

Do you all not have 93 octane? I have not driven much out west and haven't paid attention to the octane available. Everywhere I normally travel on the east coast has 93, 91 or 89, and 87 octanes available. Some stations will have 100+ race gas available as well. These are normal gas stations, nothing special. Just curious how different things may be right here in the US even.

Many areas outside of the east have 91 (AKI) as the top octane. And high altitute zones in the west have 89.

When I last traveled there, a stretch of eastern Nebraska (not high altitute) had only 87 regular or 89 E10 available with no premium at all.

There is nothing like a cross country road trip in a Z4 - roadster or coupe - try it!

Tom

[terrapen73]

Originally Posted by Tom K.

Many areas outside of the east have 91 (AKI) as the top octane. And high altitute zones in the west have 89.

When I last traveled there, a stretch of eastern Nebraska (not high altitute) had only 87 regular or 89 E10 available with no premium at all.

There is nothing like a cross country road trip in a Z4 - roadster or coupe - try it!

Tom

I have taken my Z4 Coupe on road trips of 500+ miles one way and it has been great. My previous car was a Z3 M Coupe and I bought it in Minneapolis. Flew up from NC and got in the car for the ride back home. That was a wonderful trip and really got me introduced to the new car. A little over 1500 miles one way. I gotta say the M Coupe had better seats than the sport seats in the Z4 and left me feeling better after doing 500 miles in a day. That M Coupe was just a special car.

On topic, thanks for the info on gas elsewhere.

[135IS]

Originally Posted by RPM90

It is "recommended" that you do not put your hand in a fire.
You're not "required" to not do it.
It is only a recommendation. You can do it if you like, there is no restriction on not doing it. But, then you have to deal with any consequences if you choose not to heed that recommendation.

[RoundelM3]

Doesn't your gas filler have a little tag that says "premium fuel only"? With the high compression ratio in most BMW engines, using lower-grade fuel (except in an emergency situation) is just plain dumb. And in a 1-series with a smaller tank, it's only a few dollars' difference. But again, it's your car, you can do what you want with it. Me, I've run premium fuel in every Porsche and BMW I've owned (5 Porsches, 4 BMWs) over the past 20 years.

[Tom K.]

Originally Posted by roundel335

Doesn't your gas filler have a little tag that says "premium fuel only"?

My '08 says "Premim Fuel AKI 91" without the word "only", and it also says "See your owner's manual."

The owner's manual states that:

AKI 91 is highly recommended...
Minimum AKI is 87 for 128i, 89 for 135i, and
Any brief knocking upon startup at high outside temperatures has no effect on engine life.

Tom