rpm's
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New User
Joined: Mar 2003
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rpm's
i have a 98 ford ranger 4.0 v6 4x4 supercab manual.I am towing a trailer just under my weight limit ,and the question is what should the rpm's be at while i am driving 60 mph on the highway.
thanks
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Posting Guru
Joined: May 2003
Posts: 1,437
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From: Oak Harbor WA
rpm's
Exactly how heavy is the trailer? There have been other threads about guys wanting to overload their Ford Rangers with excessive cargoes and travel trailers. Personally, I would not go with the manufacturer's weight ratings, I personally feel they exceed my safety limit. Just because it says it will haul it, doesn't mean that it will. I have a 1-ton rated to haul 14,000lb, and I don't dare haul over 10,000 with it. I would first look at safety issues - have you driven the truck with the trailer yet?
Now, if the trailer is heavy, I first would not recommend hauling the trailer at all with that truck. Second, RPM should not be that high, but to be honest I don't have a tach in my truck, so I can't give any specifics. I do know that your foot should not be at the floor. If your foot is at the floor, its time to get a smaller trailer or a bigger truck.
Now, if the trailer is heavy, I first would not recommend hauling the trailer at all with that truck. Second, RPM should not be that high, but to be honest I don't have a tach in my truck, so I can't give any specifics. I do know that your foot should not be at the floor. If your foot is at the floor, its time to get a smaller trailer or a bigger truck.
FTE Leadership Emeritus
Joined: Sep 2000
Posts: 7,298
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From: Southern California
rpm's
Your axle ratio and tire size will determine your RPM. Use this formula to find your RPM at speed.
(RPM X tire diameter)
-------------------------------------- = MPH
(axle ratio X trans. ratio X 336)
For a five speed transmission, use 1 for the 4th gear, gear ratio because it will be in direct drive. For OD gear, find out the gear ratio of your OD. Should be like .72, .80 something like that. You can find the ratio close enough if you have a tach. Get the RPM for 4th and OD both at 60 mph and do the math.
Scott
(RPM X tire diameter)
-------------------------------------- = MPH
(axle ratio X trans. ratio X 336)
For a five speed transmission, use 1 for the 4th gear, gear ratio because it will be in direct drive. For OD gear, find out the gear ratio of your OD. Should be like .72, .80 something like that. You can find the ratio close enough if you have a tach. Get the RPM for 4th and OD both at 60 mph and do the math.
Scott
