Author Topic: Fuel addicted. (Read 4250 times)

Alexx · « **on:** November 26, 2007, 12:13:29 PM »

My car is a 1991 BMW 318is. I live in Montreal. As of now, it' s cold outside. I start my car at each morning to let it run in neutral for about 10 minutes. The BMW needs 12. 5 liters to do 100 kilometers. What does your fuel consumption looks like compared to mine? I think it' s not very good for an engine this small.

Lukis · « **Reply #1 on:** November 26, 2007, 12:26:40 PM »

Mine needs over 1l pr 10km now when it is winter. Guess if you let it run for a while the cumsumption would be that much.

dude8383 · « **Reply #2 on:** November 26, 2007, 12:50:10 PM »

Quote from: Alexx;38365

My car is a 1991 BMW 318is. I live in Montreal. As of now, it' s cold outside. I start my car at each morning to let it run in neutral for about 10 minutes. The BMW needs 12. 5 liters to do 100 kilometers. What does your fuel consumption looks like compared to mine? I think it' s not very good for an engine this small.

12.5 liters to do 100kms?!

Are you sure you don't have a leak in your gas tank or something?!

That my friend is some shitty mileage right there.

tjts1 · « **Reply #3 on:** November 26, 2007, 12:51:55 PM »

Quote from: Alexx;38365

I start my car at each morning to let it run in neutral for about 10 minutes.

Don't do that. Your engine will warm up much faster if you just drive it. Consider blocking off half of your grill in the winter. Use synthetic 0w30 oil.

DaveM-sport · « **Reply #4 on:** November 26, 2007, 01:08:00 PM »

Why would you block off half of your grille to warm up the car faster???

The water in the rad doesn't go anywhere until the thermostat opens which is when the car is already hot:rolleyes:

Just sit in to the car and drive to warm it up. Just dont cane it for the first 15-30mins

tjts1 · « **Reply #5 on:** November 26, 2007, 01:30:35 PM »

Quote from: DaveM-sport;38374

Why would you block off half of your grille to warm up the car faster???

The water in the rad doesn't go anywhere until the thermostat opens which is when the car is already hot:rolleyes:

Just sit in to the car and drive to warm it up. Just dont cane it for the first 15-30mins

Try it before you knock it. It works. Blocking off part of the grill keeps more exhaust heat in the engine bay when the car is moving which warms up the engine faster therefore causes the thermostat to open sooner. You also get cabin heat more quickly which is always nice when its below freezing outside. Either way idling the engine for a 10 minute warm up is the cause of the poor fuel economy. Montreal winter is a bitch.
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ak96ss · « **Reply #6 on:** November 26, 2007, 01:34:39 PM »

Technically, he didn't say that blocking off half the grille warms up the car faster, he just said to consider doing it...

It helps the car run warmer in the winter, though - lots of folks in the northern regions do that, or have covers that go over the front of the car that partially block the radiator opening.

strad · « **Reply #7 on:** November 26, 2007, 02:03:23 PM »

Mine is 24-25 mpg mixed driving. Can be over 30 hwy. Your car will warm up fastest if you just drive it -- the only time my car idles to warm up is if I'm refilling/bleeding the cooling system. And yes, you can block off parts of the grill; semi truck drivers do that very thing to keep their engines at proper operating temps.

ApocolypseAutoEngineering · « **Reply #8 on:** November 26, 2007, 06:02:31 PM »

Umm If you look in your manual, all BMW's are start and go cars. They warm up rather quickly. Letting it idle to warm up is nearly pointless. It doesn't hurt the motor to just go on cold, those rumors are a lie. My first one had 350k miles pretty much redlining on cold start daily (I was a dumb kid I know), and it didn't die.

Quote

And yes, you can block off parts of the grill; semi truck drivers do that very thing to keep their engines at proper operating temps

Thats because diesel runs way better hot and don't rev high enough to create the friction needed to generate the necessary heat at those freezing temperatures.

gearheadE30 · « **Reply #9 on:** November 26, 2007, 08:41:53 PM »

Quote from: ApocolypseAutoEngineering;38393

It doesn't hurt the motor to just go on cold, those rumors are a lie. My first one had 350k miles pretty much redlining on cold start daily (I was a dumb kid I know), and it didn't die.

This isn't exactly true. Engines, especially a high-compression one like this, must be warm for all of the parts to be the correct size. Believe it or not, the parts will change quite a bit. If you don't let it warm up, the pistons, rings, and cylinder sleeves will wear very quickly. This and an improper breakin period are probably the most common causes of engines that burn a crapload of oil. Look around your local highschool parking lot at all of the cold cars being revved and the blue smoke flowing freely... In fact, if you look at the manual, it suggests not revving above 4k and not using full throttle until at operating temps.

ApocolypseAutoEngineering · « **Reply #10 on:** November 26, 2007, 11:19:22 PM »

Sorry let me rephrase my post. Yes the manual says not to rev past 4k until operating temperatures my point was that these cars warm up faster on the go rather than idling.

jpod999 · « **Reply #11 on:** November 26, 2007, 11:51:00 PM »

I try not to rev above 3k in the mornings. Takes my car forever to warm up.

Vladi · « **Reply #12 on:** November 28, 2007, 05:08:14 AM »

35F here, engine warms up in about 10-12 minutes by it's own. If i use the webasto heating system it warms up in 5.
Mine takes around 15 liters / 100km on a cold engine. After it's warm around 12.5 liters / 100km.

Also, the owners manual says you should not idle the cold engine more than 1 minute during winter. Remeber that the oil pressure rises once the engine revs up and the pressure is lower at idle. So if you driver the car the oil travels easier.