Surefire M4 vs M6 - almost no difference?

I am sure this must have been discussed before but how come the M6 with the regular bulb is rated at 250 lumens for 60 minutes (6 batteries), while the M4 is rated at only 25 lumens less (225) and also for 60 minutes with only 4 batteries?
Is M4 more efficient?

i was wondering the same my self.

Looks like a question for Al.

Ok, someone correct me if I get this wrong...

The M4 has 4 batteries in series, making 12 volts.

The M6 has 6 batteries in a series/parallel arrangement, making 9 volts. Less volts than the M4, but more amps.

Now consider that with their respective high-output lamp assemblies, the M6 puts out 500 lumens, while the M4 outputs a mere 350 lumens

But you can still get the 500 lumen lamps for the M4. Of course you can only run them for about 4 minutes before the batteries shut down from the heat.

But the idea is that they both run about 225-250 Lumens for an hour on the LOLAs while one only needs 4 batteries , the other needs 6 to do it.

Others CPFers said that both of the M4 LAs overall are inferior compared to the M6 LOLA and HOLA. Even the mighty M3 Turbo with it's 225 Lumen HOLA produces a whiter beam than the M4 225 LOLA. The N-62 lamp assembly which produces 500 lumens and is compatible with the M4 is no longer produced of course.

For the case of the LOLAs, it could be that lithium primaries (which have significantly higher internal resistance than li-ions) would rather produce less current from higher voltage like the M4 does than more current from less voltage like the M6. It's a whole different story for the HOLAs though... or it could just be to do with the filaments/design of the LAs themselves.

According to the Popular bulbs for current draw thread, the MN20 (M6 LOLA) pulls 2.45 amps @ 9 volts and the MN60 (M4 LOLA) draws 1.65 amps @ 12 volts. If you go straight by the math, ignoring voltage drop, the MN20 runs on 22.05 watts versus the M4's 19.8 watts.

Since the M6 uses double-stacked cells (again going straight by the numbers), each of the two stacks is undergoing a draw of 1.225 amps... so that means the M6 has a power and runtime edge compared to the standard M4, which agrees with the fact that it uses two more CR123 cells.

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In my experience the M4's beams lack the brilliance of the M6's beams.
The M6 beams are brighter, whiter, for longer.

Al

I'm considering purchasing an M4 or M6 very soon. I'm slightly favoring the M4 for a number of reasons, but I'm still very curious about beam quality, color, and runtime especially LOLA vs. LOLA. I recently had the opportunity to compare these side by side with new batteries in a store and the M6 did look slightly brighter. I'm not sure if the M6 had the new or old LOLA (since I've read that the new M6 LOLA is 15-20% less bright).

Other than the knives and tools website, does anyone else have comparisons of these using primary cells? What about runtime of the M4 LOLA vs. the M6 LOLA? How long until 50% output for each? Is the color really that different during usage? Again, I'm considering using my flashlight on primaries.

I *had* an M4 once. My only incandescent now that gets used is the M6 for the reasons that Al stated above. There is no substitute.

I understand that most people like the M6 better, but I'm looking for more concrete details or photos to help me decide... especially on the items I mentioned above.

Whenever incandescent masters Al or JS step into these threads, my experience is hear ye them. Al has already pronounced himself above and I know JS has repeatedly stated the M6's LOLA is very underrated at 250 lumens. 400 lumens is his estimate, and I can tell you for sure the M6 LOLA is MUCH brighter than the M4 LOLA. I now own two M6's and more and more I am convinced that the LOLA is the way to go for a variety of reasons, unless I really want to show off.

wmugrad28 said:

I understand that most people like the M6 better, but I'm looking for more concrete details or photos to help me decide... especially on the items I mentioned above.

Click to expand...

Check out Wquiles beamshots in this thread, they might entice you.

http://candlepowerforums.com/vb/showthread.php?t=138564&page=3

My friend owns an M4 and I think it is an excellent Light.

Based on the testimonials and beamshots of the M6 it really does seem to be a stand out Light.

Thanks for sharing.