Is a V6 better than an I6?

[The Choosey begger]

Your thoughts, thanks!

[floydarogers]

Originally Posted by anglo

Your thoughts, thanks!

As with any engineering question, the answer is: "it depends"

If you want an engine that doesn't have excess Vibration and Harshness (the VH in NVH), then the I6 is unquestionably better. However:

When it comes to packaging and weight questions, the V6 is "better", although the weight question becomes more of a wash when balance shafts are added to a V6 to solve VH.

More tradeoffs occur when a V6 is turbocharged - exhaust and/or charge pipes are longer (unless hot-V) which causes more lag, and other problems. An I6 is somewhat easier to turbocharge.

The long I6 crankshaft and camshafts may cause more manufacturing/maintenance/reliability problems than the shorter ones in a V6.

[RABAUKE]

Lets not forget about the flat 6

[ccdre]

I wouldn't use the term "better" for either one.
For an enthusiast, an inline 6 tends to be easier to work on, smooth revving and overall simpler. The packaging is lot larger for an inline configuration. Generally speaking, you could fit a V12 engine in the same bay as an inline 6.

V6 engines are more compact, more rigid but also more prone to vibrations even with counter balancing shafts.

Just my $0.02

[overcoil]

back in the early 90's when Mercedes went from inline-6 to V-6, pretty sure they said the shorter V-6 would help in front crash impact. Who know's how much was sales or reality.

then I read the inline six at extreme high rpm the crank can wobble - so probably why you don't see dedicated race engine designs that are inline-6 - at least none I can think of.

[///M Power-Belgium]

Give me a Boxer flat 6...

[wdb]

I have two of each at the moment. All have their fine points, none is quite like the other. Perhaps you could focus your question a bit.

[The Choosey begger]

Originally Posted by RABAUKE

Lets not forget about the flat 6

I'd say flat 6 is even better than v6 since it lowers the CG.

[The Choosey begger]

Originally Posted by wdb

I have two of each at the moment. All have their fine points, none is quite like the other. Perhaps you could focus your question a bit.

Handling wise...

[GuidoK]

Every engine configuration is compromised at some point.

Even handling wise there is nothing really to tell. Handling wise its not the engine, but where and how its fitted into the chassis. (and of course how the chassis is tuned to that).

IMHO BMW positiones its long I6 better into the chassis than audi does with its v6 (or toyota did with their I6 into the supra chassis)

[The Choosey begger]

Originally Posted by GuidoK

Every engine configuration is compromised at some point.

Even handling wise there is nothing really to tell. Handling wise its not the engine, but where and how its fitted into the chassis. (and of course how the chassis is tuned to that).

IMHO BMW positiones its long I6 better into the chassis than audi does with its v6 (or toyota did with their I6 into the supra chassis)

A v6 or flat six will further move the weight toward the back, what M cars desperately need.

With the driver in the car, your BMW is not 50/50 weight distribution. Besides 40/60 is optimal for traction on rwd.

Audi nose heavy is due to the quattro system, and where the engine is placed not so much because of v6's.

[GuidoK]

Yes thats what I said: Its not the engine per say, its how its fitted.

And regarding to weight distribution, I dont know if you ever drove a simca 1000, or nsu prinz, or cars in that configuration.... Traction is just half of the part regarding handling.
The other half is steering.
BMW's are designed to be great handling cars in their class, not stoplight sprinters.

In general a v6 is a compromise primarily done out of space.
It's more expensive to make, heat and flow management is more difficult, and it has more parts (more parts mean more friction too).
You can see that for example in industrial engines. 6 cyl configs are usually inline.
Same goes for 4 cylinders.

And the I6 is of course the first config that is primary and secondary balanced in its inherit design

[EJT86]

Originally Posted by RABAUKE

Lets not forget about the flat 6

Or Six Flags

[Mandi90TT]

best thing about a straight 6 is the long hoodline. I think it looks great. Brings me back to the days of the 240/260/280Z cars, which i think were pretty awesome. I kind of feel my M4 is a spiritual successor to the original Z cars

[ShocknAwe]

Originally Posted by Dave 90TT

best thing about a straight 6 is the long hoodline. I think it looks great. Brings me back to the days of the 240/260/280Z cars, which i think were pretty awesome. I kind of feel my M4 is a spiritual successor to the original Z cars

How so?

[aaaaah]

Packaging yes.

Driving experience no.

[sygazelle]

Originally Posted by anglo

Handling wise...

Handling wise, then an inline 4 is better. Somebody get the popcorn

[tock172]

I'm personally not a huge fan of V6 engines in general, but there have been some very cool ones like the Alfa Romeo Busso, the odd-firing Dauntless found in older Jeeps and of course the Buick 3800. Some of the Audi designs with 5 valves per cylinder are neat too, and so are some of the SOHC (per bank) Mercedes designs that use a 3-valve head.

That being said, my biggest complaint is that a V6, no matter if it is 60, 90 or 120 degrees is always an inherently unbalanced engine. Even with balancing shafts (which add weight and subtract performance), a V6 has always felt like a compromise to me.

Although packaging constraints limit their use, inline sixes and flat sixes are perfectly balanced. Why try to reinvent the wheel if you don't have to?

Mercedes has just launched a brand new turbocharged, DOHC, 24-valve inline six paired with a hybrid drivetrain in the next generation CLS after using V6s for close to 30 years.

[1MOREMOD]

V6 is cool for minivans and asian market vehicles

[tock172]

Originally Posted by ///M Power-Belgium

Give me a Boxer flat 6...

Two different things. Boxer engines have an individual crank pin for each piston while flat 180-degree engines share a set of crank pins.

Originally Posted by 1MOREMOD

V6 is cool for minivans and asian market vehicles

No love for the Ferrari Dino GT?

[1MOREMOD]

Those Italian bitches

[bimmer456]

Originally Posted by ccdre

I wouldn't use the term "better" for either one.
For an enthusiast, an inline 6 tends to be easier to work on, smooth revving and overall simpler. The packaging is lot larger for an inline configuration. Generally speaking, you could fit a V12 engine in the same bay as an inline 6.

V6 engines are more compact, more rigid but also more prone to vibrations even with counter balancing shafts.

Just my $0.02

So the V12 in the M760li should be able to drop into the F30? That would be one fast straight line car, but maybe not so much in the twisties. Maybe with x-drive you can get 0-60 in the 2's but would need the transmission from that car as well as the diff.