What octane gas to use in a bmw?

Anyone use higher than 87? The guy who sold me my 740IL said he never used
anything but 93, yet I see "experts" claiming that any of the premium
gasolines are not worth the extra money....

Try it. You won't like it.

wrote:
> Anyone use higher than 87? The guy who sold me my 740IL said he never used
> anything but 93, yet I see "experts" claiming that any of the premium
> gasolines are not worth the extra money....
>
>

> wrote
> Anyone use higher than 87? The guy who sold me my 740IL said he never
> used
> anything but 93, yet I see "experts" claiming that any of the premium
> gasolines are not worth the extra money....

I don't know about your bmw, but both mine have stickers on the gas door
that says premium only. Later BMWs with knock sensors can use
lower octane, but will have less performance. Your experts drive cars
with low-compression engines designed to run on regular.

Floyd

wrote:
> Anyone use higher than 87? The guy who sold me my 740IL said he never used
> anything but 93, yet I see "experts" claiming that any of the premium
> gasolines are not worth the extra money....

The octane level in gas does not indicate whether the gas is better or
worse than other grades. The word "premium" implies that it's better
gas, but it's not.

What it DOES have are more anti-knock compounds than regular. These are
needed for higher compression engines. When I first got my '94 530i I
put in regular gas (octane rating of 87) and found that it didn't quite
perform as well at lower RPMs, especially in first gear as it does using
the mid-grade gas of 89 octane. I'm sure it would do better at 91
octane, but I don't think it would be good enough to justify the higher
cost.

Give it a shot, you might see a difference.

When I tried higher octane gas with my first car (a tiny Honda 600 with
a 600 cc air-cooled engine) it just got worse gas mileage. With the 530
the gas mileage is pretty much the same with the two different grades of
gas.

Vern

I tried 87 octane in my 2.8L '98 Z3. I found no difference in performance and
mileage was as good or better than when I used 89 octane. Maybe if I did a lot
of mountain climbing heavily loaded I might see a difference, but I use just 87
now. Try a tank and see; you can always go back if you're dissatisfied.

Greetings:

I have a '91 BMW 325iX, I have always been told to use premium. I did at first
try and used regular, but the response in the car was bad. The car would stall
out on me and the performance was not there. For me, at least, the difference
was there, but for some others it makes no difference.

Andrew

wrote:

> Anyone use higher than 87? The guy who sold me my 740IL said he
> never used anything but 93, yet I see "experts" claiming that any of
> the premium gasolines are not worth the extra money....

Go lower until it starts pinging. If it pings you've gone too low.

It's probably best to use what the owners' manual says. Rarely will a car run
well on less than the manufacturer's recommendation.

It used to be that the higher grades were better quality, with better
detergents, etc. But now all grades are the same except for octane, and paying
for more octane than you need is a waste of money.

Matt O.

"VSAndrew" > wrote in message
...
> Greetings:
>
> I have a '91 BMW 325iX, I have always been told to use premium. I did at
first
> try and used regular, but the response in the car was bad. The car would
stall
> out on me and the performance was not there. For me, at least, the
difference
> was there, but for some others it makes no difference.
>
> Andrew

No difference in my '88 iX, and stock, you do not need to use premium. You
must have a chip in there. Pop the ECU out from above the glovebox and look
inside, if you find a custom chip stick with premium, otherwise try regular.

The M20B25 motor did not need premium in any application from factory.

-Russ.

In article >,
> wrote:

> Anyone use higher than 87? The guy who sold me my 740IL said he never used
> anything but 93, yet I see "experts" claiming that any of the premium
> gasolines are not worth the extra money....

This is something I wrote on this subject last year. Found it using
Google.

I have a '97 740iL. Got it new. Honest to god, if you looked through
the documentation of the car, recommendations were made for three
different grades (octane levels) of gas. I succumbed to this and
started using low octane gas after starting with high octane. Couldn't
tell a performance difference.

Before I used the low octane gas, I talked to a service adviser at BMW
asking about the confusing documentation and what he knew. He wasn't
very helpful. I also ran through the Web to look up the effects of
octane on modern cars. What I found was that the octane level was run
up to prevent ping, but modern cars are able to detect pre-ignition
conditions and control them so that ping does not occur. So the engine
is protected from pre-ignition caused by the use of sub-optimal octane
rated gas.

So what's the catch? Well, another thing that was mentioned was that
gas is not burned at optimum efficiency when the anti-knock control
features of the engine are utilized. This results in a relatively rich
(in gas) exhaust. This rich mix tends to foul the catalytic converters.
Since I didn't see anything absolute, I considered it BS, and continued
with the low octane gas until both my catalytic converters were fouled
and had to be replaced. $750 each plus labor. Fortunately, I was under
warranty. Anyway, it's been nothing but premium gas since then.

Brian

91 octane is specified. Use less, and the EMU should modify engine
operating parameters giving less power and mileage.

R / John

> wrote in message
...
> Anyone use higher than 87? The guy who sold me my 740IL said he never
> used
> anything but 93, yet I see "experts" claiming that any of the premium
> gasolines are not worth the extra money....
>
>