| bcredliner |
03-03-2016 02:49 PM |
Quote:
Originally Posted by TiAgX5
(Post 1071071)
I usually look to Car and Driver new/long term tests for "real world" 0-60 & 1/4 mile figures (been my go to for around 30 yrs).
The long term tests on BMWs almost always show faster 0-60 times, about .2 or .3 (40k miles "break-in")
Was unable to find a long term test on the 4.6is, new, C&D found 6.5sec 0-60 (would be as Brian stated above around 6.2 after break-in).
C&D did a long term test on the 4.4, found the 0-60 to be 6.7sec after 40k miles.
Service Time
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My reference is the BMW factory rating of the X5 4.6, not an any miles after calculation. I assume the Bimmerworld quote was intended to be the same. Performance after any amount of miles will vary notably if only considering how those miles were driven. 6.7 could just as well have been 7.2 or 6.5. Personally, I don't think that information is meaningful. And that does not consider all the variables similar to dyno runs used to declare HP/TQ.
Dyno runs on engine or chassis dynos involve using a formula to extrapolate estimated HP/TQ. Generally engine dynos are more accurate than chassis dynos. There are several different technologies applied to various engine or chassis dynos. Brands and dynos within a brand do not deliver the same results. And there are too many other variations to list but here's a few---calibration of dyno, formula in software, how tight the tie down straps are, tire pressure, torque convertor slip, tire size, diff ratio, tire slippage, CFPM of air the shop forces into the engine, if or what they hook the exhaust to, barometric pressure, temperature, humidity, operator expertise, etc. All dyno results are at best an guesstimate. Same is true of A-B timed runs. IMO comparisons to other vehicles are just for fun or a good way to initiate a d*&k dance.
I don't consider dyno runs to be useful except to an individual that wants to see the results of their mods or to mess with the tune to see if there is more there to get out.
I think the only way to know who is faster is to line 'em up and cut them loose and see who gets from A to B first. Even then it is only the results of the race on that day and those two vehicles.
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