I6 or V8

[ekimv65]

Now you guys are making it sound like there will be hell to pay if I but a V8. Are they really that bad?

[FSETH]

I agree with you JCL regarding the balance of the inline 6 and V-12. I have had a few BMW inline sixes and my parents have had two BMW V-12's for a long time, but seeing as this was posted in the e53 forum, that is what I was trying to focus on. As far as the e53 is concerned, there is a night and day difference in the overall performance and seat of the pants feel between the 6 and the 8. The 6 cylinder available in the e53 was way underpowered for the heft of the X, imo. Not trying to knock it. It is a good vehicle, but not enough oomph for me. Actually, I wish I had either the 4.6is or 4.8is...more power (insert Tim Taylor grunt here). The only plus for the 6 was the availability of the manual trans, but that benefit was outweighed by the horse power and torque of the 8, imo.

[JCL]

Originally Posted by ekimv65

Now you guys are making it sound like there will be hell to pay if I buy a V8. Are they really that bad?

They aren't bad at all. Maintenance costs will likely be a little higher, fuel consumption is a little higher in the real world, resale may not hold up as well once fuel prices go back up, but those are all small differences.

My comment was directed at those who seem to think that the V8 is the only way to go, and that there is no reason to buy the I6. The I6 is certainly a smoother engine. It isn't as fast, but since it is lighter is handles slightly better. My reasoning was that if I wanted to go fast, I probably wouldn't start with a heavy SUV in any case. I never felt like my E53 3.0 needed more power, but then I had other (faster) vehicles at the same time.

Something like 70% of all X5s were sold in North America with the I6 engine, so most people have that as their baseline. 225 hp is more than my Explorer had, for example, so it felt fine. This forum is somewhat biased towards owners who like to mod their vehicles, accelerate quickly, etc, and so the poll reflects that. You asked a biased group, and got a biased answer. But at the end of the day, you need to decide, not us. Drive them both, and decide.

[_XS3C_]

Originally Posted by ekimv65

If money was not a hindrance, I6 or V8.

MPG:
'01~'06_ I-6 engine = 16/21 MPG
'04~'06_ V8 engine = 16/22 MPG
--------
power:
I-6 = 3.0L 225HP/ 214 torque
V8 = 4.4L 315HP/ 324 torque
-------
performance0-60MPH:
I-6 = 8.3 sec
V8 = 6.8 sec
-------
higher end or extra equipment for example:
I-6 = 5 speed step. AT
V8 = 6 speed step. AT + self level R. susp .......
-------
so which one is more: economical /powerful/ better equipped ........

The inline 6 engine is well balanced and great engine that is just perfect for compact size car, but when that same engine is swapped in 5.000 LB vehicle almost twice the weight it is way different story !
OVERALL:
I6 engine is PERFECT for car !
V8 engine is PERFECT for SUV/truck !

[JCL]

In the real world, the V8 does not get the same fuel consumption as the I6. The (theoretical) EPA figures are close, but that is a simulated run, and does not account for the greater weight of the V8 model, or the greater power (which drivers tend to use). You are claiming more power, and the same mileage. You can't have both.

[_XS3C_]

Originally Posted by JCL

In the real world, the V8 does not get the same fuel consumption as the I6. The (theoretical) EPA figures are close, but that is a simulated run, and does not account for the greater weight of the V8 model, or the greater power (which drivers tend to use). You are claiming more power, and the same mileage. You can't have both.

"The theoretical EPA figures" - [from page 79 in the OFFICIAL '06 BMW X5 brochure] will be then close for the I-6 engine as well .......
Only 231lb is the difference between N62 V8 engine X5 and I-6 - where the V8 have the as called "CLOSE" economical MPG to the I-6 with the extra on top 90HP power [when compared to the I-6], and I'm not talking about the perfect weight distr. on N62 V8 X5's ~ almost 50/50 vs also almost 48/52 for I-6 E53's.
IMO and the FACTS are that N62 V8 engine [when compared with the I-6 engine], instaled in E53 shell - DOES HAVE BOTH: mileage and power [HINT- 6SP AT does make some difference at the MPG to ] !
[IMO N62 V8 E53 - PWR/MPG is as CLOSE to perfect as 98.9% ....... ]


heck, we should compare I-6 SUPERCHARGED engine with V8 engine to see the PWR/MPG difference, otherwise it is apples vs oranges

[Fraser]

Give me a break! Writing off the V8 because it isn't perfectly balanced is like saying that Kim Kardashian is unbalanced because her left nipple is two microns bigger than her right nipple.
The fact is that both the IL6 and the V8 (being a 90-degree) have perfect balance of the primary and secondary inertial forces, the big factors in determining if an engine is smooth or not. And while the IL6 also ticks both boxes in terms of perfect balance of primary and secondary free moments of inertia whereas the V8 scores a '10 out of 10' for secondary free moments but only an 'eight of ten' for primary free moments, is no big deal either way.
On the consumption issue there's so little in it that it's irrelevant. Much more significant is the fact that the V8 is more immediate in its response and a much better 'drive'. I could live with a 6 but only with a manual, preferably the post-'04 six-speeder. For me my '05 3.0d beats the pants off the petrol six or either 4.4 but that's another story and irrelevant here...

[JCL]

Originally Posted by _XS3C_

"The theoretical EPA figures" - [from page 79 in the OFFICIAL '06 BMW X5 brochure] will be then close for the I-6 engine as well .......

The EPA figures for the two vehicles, and which are the basis for the brochure, are very theoretical. They are measured on a test cycle, and then adjusted by a correction factor. No vehicle actually achieved the published number. Check out the test methodology. The numbers are based on a test cycle which:

• is on a dynamometer, which does not account for the vehicle weight difference
• is at a pre-programmed acceleration rate (which is the same for both vehicles) that is very slow, thus not using any of the V8's hp advantage
• is so slow that the additional top gear doesn't come into play

That is why the theoretical figures are the same, and why I call them theoretical. It is easy to check, look and see how many members in the real world are getting the same mileage on the two vehicles. Sure the V8 has more hp. But if you take advantage of it (which burns more fuel, that being how power is created....) you won't get the same mileage as the I6.

So, your FACTS are theoretical, and not available in the real world. But they did help BMW sell more vehicles.

No argument that the V8 is faster.

[JCL]

Originally Posted by Fraser

Give me a break! Writing off the V8 because it isn't perfectly balanced...

You can't tell the difference in smoothness between an I6 or V12, and a V8, when driving them?

[Daka]

One more time....I have owned at least 20 (maybe more) 6 cylinder BMW's over the past 35 years,
They have been making this engine (with improvements) FOREVER.
On an X5 IN THE USA I really think the V8 with its problems is TOTALLY UNNECESSARY....UNLESS...you are towing a B F T (Big f Trailer)
My personal X5 (06 Sport/Prem) has more power/acceleration than I need for any kind of use it would be put to.....V8 (overkill)