M38 vs MB

ClarkJ · Post by **ClarkJ** » Sat Oct 22, 2005 6:45 pm

I was talking with a guy and he told me a WW2 Jeep goes faster than a M38.Any truth to that?Clark.

Bob_C · Post by **Bob_C** » Sat Oct 22, 2005 7:57 pm

Ehhhh....

Both are geared down so insanely low with low horsepower engines that I doubt that the speed difference between the two vehicles is noteable.

MajBen · Post by **MajBen** » Sat Oct 22, 2005 8:00 pm

Hi, I was thinking that that there is a difference in the gear ratio but lopo many be right in that there is no noticeable difference. SF Ben

Bob_C · Post by **Bob_C** » Sat Oct 22, 2005 8:54 pm

Well now, wait a sec.

MB has a differential ratio of 4.88 to 1...so every 4.88 driveshaft revolutions = 1 axle revolution.
M38 (and M38A1) have a differential ratio of 5.38 to 1.

So yeah, I guess the MB would go faster in theory.

But id still doubt youd even notice it. 63 or 65 miles an hour - what difference does it make?

Post by **wesk** » Sat Oct 22, 2005 11:04 pm

You guys forget that the tire diameters are different. The MB with 4.88 gears has a 6.00x16 tire and the M38 with 5.38 gears has a 7.00x16 tire. This almost effectively canx any advantage or disadvantage each jeeps gearing has over the other. The real reason the MB was a little fast at the top end was it was considerably lighter and the engine wasn't turning a dual belt 24 volt 25 amp generator. The M38 would probably accelerate a litttle faster. However when the Army saw the M38A1 performance figures they dumped both the MB and the M38 in favor of the A1's F134 with 72 HP.