Regular gas vs. Premium gas

[Drewthebull]

This is a question for the mechanics. With gas prices roughly $4.68 per gallon, my question is, how harmful would it be to use regular gas in my 525i?

Internet research shows there is not much of a difference when you use regular gas vs. The more expensive premium gas.

Your help is greatly appreciated.

[wcr3d]

Having tried it myself, it will run ok but you'll notice the difference.

[beshannon]

I run premium gas because that is what the owners manual says to run.

The few extra pennies per gallon are worth it to keep the car running properly, to me at least.

[JayArras]

Read this on another board, so opinion is not my own:

"Most of the later model BMW's (post 2004) are equipped with knock sensors. If the octane level in your gasoline is too low, the knock sensors will sense when engine knock is evident and correct for it by retarding the ignition timing. The result of this is minute, and should be imperceptible to most owners in that there will be a very small reduction in power output of the engine. In no way does retarding the ignition cause any harm to the engine. "

Occasionally, I would put regular in my E39 when I owned it, and DID notice a reduction in responsiveness upon acceleration, but never hesitation. Have owned the E60 for a year and a half now, and it has never seen regular.

[Gilgorm]

You have a premium car so put premium gas in it.
Your manual should tell you 87 Octane minimum but 91 Octane is preferred. In the 08 manual there is a warning about engine knock.
You will notice the difference with a lower grade and many have reported worse gas mileage which negates the up front cost savings which in my opinion are minimal.
BTW, regular here in Ontario is $4.59 today which is the lowest it has been all summer, which was typically $5.06 plus $.16 extra for premium.

[mbhurley]

Where I live. typically you can only buy 93, 89, and 87 octane. The 87 octane is typically $0.25 less then the 93 and the 89 is ~$0.10 less than the 93.

Since you only need 91 octane, one way to get it is to mix 93 and 89 at equal portions and save ~ $0.05/gal. over just adding 93. Not a lot, but it is a savings.

The other way is to add a mix of 87 and 93. Do it at 50/50 and you save $0.12 over straight 93, but only get 90 octane. Do 2/3 93 and 1/3 87, you get 91 octane, and save about $0.08 cents over straight 93. $0.08/gal over 16 gals (typically fill on 18 gal tank) is $1.04. Again not a lot, but if you get 24 mpg avg driving, and drive 12000 miles year, that's 500 gal or $40 extra in your pocket.

Adding more octane than what the engine requires doesn't buy you anything in performance unless you have the engine tuned for it.

[White94RX]

I've been using regular since I've had my E60. Like ten months now. I don't know what my ex wife put in it when she drove it.

[White94RX]

I've been using regular since I've had my E60. Like ten months now. I don't know what my ex wife put in it when she drove it.

[bimmerzone]

Here is my 2 cents....
Use Premium gas !! the car needs it.... while it has knock sensors to take care of accidental use of regular gas, it tunes down the performance of the engine. (no real harm)

[e30ncsu]

The car will be fine on regular, absolutely 100%

[in transit]

If premium is twenty cents more per gallon, you save $2.00 when you buy 10 gallons. Stop being cheap and buy the good stuff.

[Gustavoerod]

If anyone is worry about 20 cents savings on gas, them why did you buy a BMW? Didn't you think about it first? Go trade it for a smart car. I don't want to sound like a heartless man but gas should not be your worry when purchasing these vehicles, you should know, that you will be paying for "the ultimate driving machine" somewhere.

[notopm3]

Does it really matter if you spend $70 or $72 dollars on a tank of gas? That's the difference between regular and premium. Just use the good stuff.

[Drewthebull]

Thanks guys...your input is greatly appreciated. The reason this question came about was filling up my wife's car, Chevy Tahoe, and my bimmer. Not to mention my two sons who can eat all of my groceries before I unload the car.

In most cases you guys are right...it's only a $2 difference... but in a time when the cost of living goes up, every dollar counts.

[crewzer]

As noted above, the knock sensor(s) will retard ignition timing if regular (87 AKI) gas is used instead of the recommended "super" gasoline (91 AKI or better).

A possible side effect is that fuel economy may suffer. So, it may cost less to fill up with regular (or mid-grade), but you may achieve fewer miles per tank, so you'll fill up more often, and your cost per mile may not improve.

Separately, an adjustment to driving style might help. Once I pass the "noobie gate", I'll post a picture of my 2006 E61's dash showing 501.8 highway miles on a single tank of Chevron 93.

HTH,
Jim / crewzer

[pcy]

...
A possible side effect is that fuel economy may suffer. So, it may cost less to fill up with regular (or mid-grade), but you may achieve fewer miles per tank, so you'll fill up more often, and your cost per mile may not improve.
...

That's what I always thought.
However, on my '06 530i, I get 24 MPG (with mixed highway and local driving) with 93 Octane and I get the same 24MPG with 87 Octane as well. I only switched to 87 gas recently; I've used for 3 full tanks of gas. I see no significant difference in power.

I believe premium gas has additives+detergents to keep fuel system clean. This may be worthwhile for me more than the MPG. Unfortunately, I can't quantify the benefits of additives/detergents. May be just peace of mind.

[e30ncsu]

most producers have the same additive package in the regular and premium

[mbhurley]

Separately, an adjustment to driving style might help. Once I pass the "noobie gate", I'll post a picture of my 2006 E61's dash showing 501.8 highway miles on a single tank of Chevron 93.

HTH,
Jim / crewzer

Not unrealistic. I routinely get 480 miles/tank using 91 Octane with roughly 80/20 hwy/city when I head to Philly from Boston. That is averaging 70-80 mph on the highway with a couple of stops and the last 20 miles or so in back country hilly roads. I am sure if I stayed on the highway, I could easily get 500+ miles without too much effort.

[crewzer]

I routinely get 480 miles/tank using 91 Octane with roughly 80/20 hwy/city when I head to Philly from Boston.

Excellent!

We've had our E61 for ~13 months. I can consistently do 28 - 31 mpg (light load, no A/C) on the highway running on 93 AKI. The best I've done on 89 AKI is 28, and the actual mix (89 + 93) was ~90.

Our average over the past ~12K miles has been 24, with ~2/3 highway and 1/3 city/suburbia.

I read many complaints about the E60/E61 fuel economy. My take is that 500+ miles in the AWD wagon from one tank is not common.

We like the car!!

Regards,
Jim / crewzer

[JayArras]

In most cases you guys are right...it's only a $2 difference... but in a time when the cost of living goes up, every dollar counts.

+1

There's no reason why you shouldn't try to save a buck where you can, regardless of whether you own a bimmer or a smart car. It's not a matter of being cheap, it's a matter of being sensible and getting the most of the money you earn.

That being said, it sounds like many on this thread will have to agree to disagree .

[White94RX]

Actually the difference in price is more like 30-35 cents around here. So, being my car has probably 18 gallons or so, and it usually take 16 gallons to fill it, that makes $5.20 assuming premium is 32.5 cents more than regular. When I fill up probably 4 times a month, that's $20.80 per month. Multiply that by a year makes $250 bucks.

It comes down to saving money where I can. I still get over 30 mpg on the highway. And my car is a 525 anyway, so it's not really a "performance" machine. I can't tell the difference between regular and premium anyway. I'll keep the extra twenty bucks a month. Actually probably closer to $300 bucks a year when you factor in traveling for holidays and vacations.

[mbhurley]

Actually the difference in price is more like 30-35 cents around here. So, being my car has probably 18 gallons or so, and it usually take 16 gallons to fill it, that makes $5.20 assuming premium is 32.5 cents more than regular. When I fill up probably 4 times a month, that's $20.80 per month. Multiply that by a year makes $250 bucks.

It comes down to saving money where I can. I still get over 30 mpg on the highway. And my car is a 525 anyway, so it's not really a "performance" machine. I can't tell the difference between regular and premium anyway. I'll keep the extra twenty bucks a month. Actually probably closer to $300 bucks a year when you factor in traveling for holidays and vacations.

+1.

30-35 cents/gal here also. I have a 530xi sedan, and while I notice a little difference in performance/mileage, if I use 87, if I mix 93/87 to get 90, I don't compared to 93. So I save $0.15/gal or $75/year on 500 gal of gas/year.

[bbuchho90]

+1

There's no reason why you shouldn't try to save a buck where you can, regardless of whether you own a bimmer or a smart car. It's not a matter of being cheap, it's a matter of being sensible and getting the most of the money you earn.

That being said, it sounds like many on this thread will have to agree to disagree .

To me its a matter of being sensible and getting the most out of your engine, by putting in the recommended octane. I'd rather spend the extra $200 a year to do so.

But like you said, looks like people just have to agree to disagree

[e30ncsu]

http://www.cartalk.com/content/premium-vs-regular-1
http://lifehacker.com/5846880/should...-gas-in-my-car

you have a knock sensor and a computer, it won't hurt it.

[in transit]

Are we really talking about saving 20.00 per month? I'm sure most people blow 20.00 per month on any combination of beer, coffee, soda , lunches out, magazines, newspapers, girl scout cookies, etc. 250/365=1.46 a day.