LSI Posted February 21, 2014 Share Posted February 21, 2014 Dealer has Mack with M-Drive single od,445E,2:66 rears.Also has a Volvo with 445EX,3:08 rears and I-Shift single OD.Which one of these combinations looks best.I run 65 to 63 in Wi and 5 states around.Denver once in a while and Sc from central Il. My ISX is sending me to the poor house.Money is not the problem its the down time.I'm still looking at the 2:66 direct but Keven Rutherford says he likes the 2:66 single OD.Which is confusing cause he always goes for direct drive.I've got an e-mail to him to clear this up. Quote Link to comment Share on other sites More sharing options...
kscarbel2 Posted February 21, 2014 Share Posted February 21, 2014 Overdrive versus direct drive is an old debate. Big fleets like Wal-Mart and Schneider National spec direct drive exclusively. The trade-off here is fuel economy versus drivetrain reliability. I feel direct drive wins at low GCWs, and overdrive wins at higher GCWs.Many tests have been conducted with fleets, and it was hard to find a difference between overdrive and direct drive because so many other variables play into the equation. It's no surprise that the routes driven and the drivers were found to be larger variables than overdrive versus direct drive. Quote Link to comment Share on other sites More sharing options...
rsb502 Posted February 21, 2014 Share Posted February 21, 2014 The math doesn't lie, more torque to the ground with a direct, as for Volvo versus Mack.....well I think you know where most of us stand there. The Volvo should pull better since it has lower overall gearing, the Mack may get better fuel mileage but I doubt it running 65. The issue here will be lugging or having to drop a gear constantly, without knowing tire size its hard to figure rpm @65mph but I wouldn't buy an OD truck with anything lower than a 3.36 with a 42" tall tire. I'm sure this will spark some debate but if you find somebody running 2.66 rears with an OD trans and ask them what their rpm is at 65 that should help you out. I would want my cruise rpm no lower than 1300-1400, any lower and any kind of rise and you'll need to drop a gear. I personally like a 1400-1600 rpm cruise speed depending on trans so you have the power to maintain road speed on rolling hills without changing gears or lugging constantly but I live in a hilly area. 1 Quote "Any Society that would give up a little LIBERTY to gain a little SECURITY will Deserve Neither and LOSE BOTH" -Benjamin Franklin"If your gonna be STUPID, you gotta be TOUGH" "You cant always get what you want, but if you try sometimes you get what you need" Link to comment Share on other sites More sharing options...
mack mhe9 Posted February 21, 2014 Share Posted February 21, 2014 Yes what he said. Quote Link to comment Share on other sites More sharing options...
LSI Posted February 21, 2014 Author Share Posted February 21, 2014 The math doesn't lie, more torque to the ground with a direct, as for Volvo versus Mack.....well I think you know where most of us stand there. The Volvo should pull better since it has lower overall gearing, the Mack may get better fuel mileage but I doubt it running 65. The issue here will be lugging or having to drop a gear constantly, without knowing tire size its hard to figure rpm @65mph but I wouldn't buy an OD truck with anything lower than a 3.36 with a 42" tall tire. I'm sure this will spark some debate but if you find somebody running 2.66 rears with an OD trans and ask them what their rpm is at 65 that should help you out. I would want my cruise rpm no lower than 1300-1400, any lower and any kind of rise and you'll need to drop a gear. I personally like a 1400-1600 rpm cruise speed depending on trans so you have the power to maintain road speed on rolling hills without changing gears or lugging constantly but I live in a hilly area.Tires are 295/75 22.5 Quote Link to comment Share on other sites More sharing options...
LSI Posted February 21, 2014 Author Share Posted February 21, 2014 Tires are 295/75 22.5Per eaton with 2:64's .78 @ 1300= 73.4 mph .78 @ 1100= 62 mph 1.0 @ 1300= 57.3 mph 1.0 @ 1100= 48.4 mph 3:08 .78 @ 1300= 62 mph .78 @ 1100= 57.5 mph Quote Link to comment Share on other sites More sharing options...
LSI Posted February 21, 2014 Author Share Posted February 21, 2014 The math doesn't lie, more torque to the ground with a direct, as for Volvo versus Mack.....well I think you know where most of us stand there. The Volvo should pull better since it has lower overall gearing, the Mack may get better fuel mileage but I doubt it running 65. The issue here will be lugging or having to drop a gear constantly, without knowing tire size its hard to figure rpm @65mph but I wouldn't buy an OD truck with anything lower than a 3.36 with a 42" tall tire. I'm sure this will spark some debate but if you find somebody running 2.66 rears with an OD trans and ask them what their rpm is at 65 that should help you out. I would want my cruise rpm no lower than 1300-1400, any lower and any kind of rise and you'll need to drop a gear. I personally like a 1400-1600 rpm cruise speed depending on trans so you have the power to maintain road speed on rolling hills without changing gears or lugging constantly but I live in a hilly area.2:66 rears with M-Drive and single od at .78 at 65mph rpm's should be about 1100 in od Quote Link to comment Share on other sites More sharing options...
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