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Discussion Starter #1
So my job is only 10 blocks away from my home. I've been reading here that short trips are not good due to carbon build up and the battery not fully charging. Do you guys think it would be better on the engine and battery to take a longer route to and from work everyday or am I being overly dramatic?

Thanks.
 

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So my job is only 10 blocks away from my home. I've been reading here that short trips are not good due to carbon build up and the battery not fully charging. Do you guys think it would be better on the engine and battery to take a longer route to and from work everyday or am I being overly dramatic?

Thanks.
I would get a ctek charger and put it on your car once per month to keep the battery good. As far as the Carbon build up I don't think there is a ton you can do. Drive the car hard when you go other places than work and on longer trips. But a bottle of techron in the gas every 3 fill ups. Other than that, don't worry, and just enjoy your car.
 

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Need to warm that engine up!

Every TSB that references battery issues refers to customers taking short trips as a possible cause. I believe that you should, at a minimum, get the engine temperature up to normal operating temp at least every 2-3 days. That means at least 30 minutes of driving. My commute is an hour each way so my car gets a daily warm up and good battery charge.

Jerry
 

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Discussion Starter #4
I would get a ctek charger and put it on your car once per month to keep the battery good. As far as the Carbon build up I don't think there is a ton you can do. Drive the car hard when you go other places than work and on longer trips. But a bottle of techron in the gas every 3 fill ups. Other than that, don't worry, and just enjoy your car.
Thanks. I just got some Techron this weekend. They had buy one get one free for anyone els that uses it.
 

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Discussion Starter #5
Every TSB that references battery issues refers to customers taking short trips as a possible cause. I believe that you should, at a minimum, get the engine temperature up to normal operating temp at least every 2-3 days. That means at least 30 minutes of driving. My commute is an hour each way so my car gets a daily warm up and good battery charge.

Jerry
Sounds like a plan.
 

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i also drive short trips (2mile one way)never had issues with battery on previous 7 or any bmw. but something to as to driving it a lot. i avg 18K per yr. so as you can see i take car out on open highway a lot.
 

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Unfortunately 10 blocks, 5x a week, twice a day isn't even a blip to warm up the car or charge the battery. In the spectrum of ICE (Internal Combustion Engine) wear from worst to best is:

Barely warming up/short commutes... warmed up, but with stop and go traffic.. warmed up long distance drives.

But this is true for any car (engine/trans/battery), it's just that BMWs always tend to be most sensitive to this equation.

BUT, here's the good news: if you do drive it that little on an annual basis, it might be years before you see the effect of that. Say you only drive it 5k annually, it would take you 10 years to wear the engine/trans down enough to probably notice it. Compare that to someone who drives 15k annually, but in stop and go traffic, by year 3... good luck!!

If you CAN balance it out a bit, with long distance runs (as someone else noted), that would help. But again, not sure how long you're going to keep it, but you probably won't see the effect of it before you'd sell it anyway.

Some common issues of that type of driving (not specific to BMW, but in general) are sludging, carbon buildup, catalytic converter wear (you will have built up a lot of condensation that doesn't have a chance to burn off effectively), transmission issues. The highest wear on an ICE occurs during the warm-up period and figure that's the only time you're ever really driving it. My dad used to warm up his car for 15 minutes before driving it, every morning. Only problem is that it didn't do anything for the trans. Auto manufacturers DO NOT recommending warming up anymore, but just to drive slow/gently until it does. HOWEVER, this is mostly due to EPA regs (can you imagine thousands of cars idling every morning?).

OK, feel free to stop reading now, unless you want to know way more than you need to enjoy the car!

On a side note, regarding carbon build up with DI engines, the fuel never touches the top of the intake valves, rather the injectors pump the fuel directly into the cylinders, where ignition occurs. This leaves the valves to accumulate carbon over time. On non-DI engines, the fuel is sprayed into the top of the intake valves, which then coats the valves, acting as a "cleaner" this is where all those wonderful techron and other additives come into play. Sadly, while it's good for other things, those additives won't help with a carbon build up issue since those additives never touch the "back" of the valves (except for one key part, read on). And of course as the carbon builds up, it can restrict air volume or change air flow profiles into the cylinders which would result in drivability issues.

Truth is, there is no way to avoid it (various degrees of it) on a DI engine, so don't worry about it. Walnut blasting (ie mechanical means) is the only effective solution to longterm carbon build up (but what defines build up and what your tolerances are for same is relative). Even soaking carbon covered valves in numerous chemicals don't actually result in an easy removal of it (it is..... after all.. CARBON--think diamonds!!) and would require the intake be taken apart, so walnut blasting is still a preferred option.

But DI is great for power and mileage (as it's so much more efficient). So now companies are considering a mix of DI and old school Port FI (whereby fuel can still be sprayed ON TOP of the intake valves rather than only INSIDE the cylinders). But that just sounds overly complex to me.

Frequent oil changes are important to alleviate CBU as it ensures the proper timing for camshaft/valve/etc (low oil or bad oil can really mess up timing even by fractions of degrees).

And good quality gas is very important as it allows for a cleaner burn. With bad gas, the ignition in the cylinder can be dirty, resulting in a lot of carbon, as the intake plunges ever so slightly into the cylinder, that carbon can coat the top of the valves. Hence CBU. Unfortunately, additives will do nothing to remove existing CBU on a DI engine. But starting off with good quality gas can help prevent it.

Finally, it's possible to tune ECU (engine management software) so that the ignition occurs exactly at the right time in the valve open/close phase to help restrict carbon blowback onto the valves. But DI engines are always straddling a fine line between efficiency, power and misfires. Throw in possible bad injectors and other N63 quirks and a slightly out of timed engine can have CBU.

One thought to help prevent CBU is driving the car HOT (Wide open throttle, high RPMs, good quality gas, perfectly maintained engine). The idea, some say, is that if the engine is running hot and under WOT, carbon can't as easily stick to the back of the valves. The problem with this is that it again won't help with any existing CBU and will result in a myriad of other parts wearing down or failing--if done at the theoretically needed intervals to make it "effective."

As CBU becomes more an issue, more places will offer a cleaning service and the prices of that will go down. While it generally will only result in a loss of power, it's only when it starts generating codes which result in you not being able to pass a SMOG test, that it becomes a real problem.
 

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Discussion Starter #8
Very knowledgable post. Thanks aom.
 

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very good information. this is what forums are suppose to do. inform us that don't know ...thanks for that. very much appreciated.
 

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From an experience standpoint, I did the same thing for the first 5 years. My office was about 10 blocks and in the city. The only issue I've had (knock on wood) was that on one of the frigidly cold days in Chicago a few years ago the warning went off that the battery was low. The car started with no problems though. I drove the car around for a while on that day (with some highway driving) and everything was fine after.
 

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It's not everything, but be sure to use the right fuel to fight carbon build-up.
the only gas I put in my car. I was using Costco on y 08 and had the fuel injectors replaced. mechanic told me to stop using it. I understand they have detergents in gas now but I do not chance it.
 

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Shell and Chevron only

Even before I got my 750, had an S550 and could feel the difference when I used Shell versus the gas at Sam's club. (Sam's was across from MB dealer in Florida). The only gas I've put in 750 is Shell with the only exception being if I can't find a Shell while traveling I'll use Chevron. Might not make any difference, but I'll stick with Shell for my car. :thumbup:
 

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whughes
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Check toptiergas.com for good gas.

my son used to drive 4 miles to work, one of the side effects of not getting the engine hot is moisture build up in the top of the heads. it looked like he had water in his oil, lots of orange foam, he started taking a lap around Baltimore on his way home once a week to clear it up.
 

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Not all top tier gas are created equal. When top tier standards first came out, only 5 brands met their standards. Then, many of the other brands improved their fuel to meet the minimum top tier standards, such as Costco. The lower end of top tier reduces the rate of carbon build up while the higher end actually reverses current carbon build up.

It's only Shell or Chevron for me. I guess Texaco too since they use the exact same fuel as Chevron.
 

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I'm not condoning the following, but I will share my efforts in improving the quality of gas I put in my 750 and all my vehicles.

I only use premium from Chevron, but I also add 6 ounces of Lucas gas additive AND about a quart of Xylene to every full tank.

Xylene and tuolene are generally known as paint/lacquer/epoxy thinners, but from my understanding the gas companies commonly add these to fuels as octane boosters/fuel stabilizers.
Why do I "trust" this concoction? There are plenty of online resources, particularly in the turbo communities, that speak to the science of the hydrocarbon strings much better than I could. Evidently it has been around for years, and they use up to a gallon for every 10 gallons to raise the octane levels up a couple of points.

From my experience I can't definitively conclude there is an increase in power or an increase in MPG, but I do believe there is some improvement. However, I did often experience the rough idle at standstill, and that has subsided greatly.
Will it help with carbon deposits... not sure. (In fact if it does it could just cause damage to the cats if unburnt.) I don't think it will make the deposits worse.
Again, just my two cents. Been running this concoction for about 3,000 miles with no ill results.

Sent from my SM-N920I using Tapatalk
 

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I'm not condoning the following, but I will share my efforts in improving the quality of gas I put in my 750 and all my vehicles.

I only use premium from Chevron, but I also add 6 ounces of Lucas gas additive AND about a quart of Xylene to every full tank.

Xylene and tuolene are generally known as paint/lacquer/epoxy thinners, but from my understanding the gas companies commonly add these to fuels as octane boosters/fuel stabilizers.
Why do I "trust" this concoction? There are plenty of online resources, particularly in the turbo communities, that speak to the science of the hydrocarbon strings much better than I could. Evidently it has been around for years, and they use up to a gallon for every 10 gallons to raise the octane levels up a couple of points.

From my experience I can't definitively conclude there is an increase in power or an increase in MPG, but I do believe there is some improvement. However, I did often experience the rough idle at standstill, and that has subsided greatly.
Will it help with carbon deposits... not sure. (In fact if it does it could just cause damage to the cats if unburnt.) I don't think it will make the deposits worse.
Again, just my two cents. Been running this concoction for about 3,000 miles with no ill results.

Sent from my SM-N920I using Tapatalk
That's actually what most octane in a bottle consist of and by adding it all you are doing is helping the engine run with better efficiency as it's octane rating has been raised slightly and the engine can run at a higher boost level. I wonder what the BMS box plus a mix of E85 and Premium would do for the 750! I'd imagine upwards of 550HP!

The issue at hand is short trips, and due to the nature of the F01/02 charging system driving short distances will not charge the battery enough.
 

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whughes
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sticking to the short trips issue, BMW now says to change the battery at every oil change,
 

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Discussion Starter #19
sticking to the short trips issue, BMW now says to change the battery at every oil change,
I'm at 48k miles. I wonder if they'll replace mine before the warranty is up since they didn't change it the last oil change which was about 3 months ago?
 

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whughes
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I would check with your SA
 
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