I see the discussion list is down again so wanted to use the message board for my question. At what speed should i shift into overdrive? I have the 5 speed stick and i usually shift into overdrive on the freeway at about 50. Would i harm the engine if i didn't use overdrive on the freeway? Thanks for your responses. Bob

 

I let mine shift in at around 40. Easier on the engine (1100 RPM at 37MPH for mine) and gas mileage. Drive whatever gear you feel comfortable in - it's a Truck!

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1999 F-250 XLT Super Duty Crew Cab Long Bed
V-10, Automatic 4R100, 4.30 Limited Slip.
GVW = 6700# Towing Capacity = 13,300#
4 Wheel ABS disks + Reese 15K hitch
Dark Hunter Green. Ford Running Boards.
Grey Rhino-Liner. Captain's Chairs. CD+Tape
Polished Stainless Steel Wheel-well Molding http://members.home.net/jchartier/jnctrk.html

 

Bob,
I have the 5spd, a 3.55 rear end and the stock 23570R16 tires. I shift from 4th to 5th at 42mph like the owners manual says. If you have the 3.08 rear end, you could shift at a higher speed (like 42*3.55/3.08 = 48.4mph).

I would definitely use overdrive on the highway as the high rpms of 4th gear would probably reduce the engine life.

What is your powertrain setup (rear end, tire size, etc)?

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'98 F150 XLT S/C 4x4 4.6L 5spd 3.55 Lt Denim Blue, Raven camper shell

 

Happy Camper- rear end is 3.08, tire are stock235/70rx16l. Truck seems to "lug" when shifting nito overdrive at 40, but will try 45 or so.

 

I have the 4.9L 5spd 3.08 axle, I have ran 3rd all the way to 70mph, 4th to 85mph and finally shifted to overdrive at around 85mph. If this straight 6 with it's long stroke can handle that I'm sure the 4.6 will handle that and more. I need to put a tach in this thing, I can't imagine why a 5spd doesn't come stock with a tach?

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1995 F150 4x2 4.9L 5spd Twin I-Beam Front Suspension Gabriel Sport Ride 3 stage Nitrogen Shocks 3.08 rear axle, Autolite Platinum Plugs, Exact Wires. Goodyear Workhorse Extragrip Tires,

 

I've got the same setup as you (rear-end and tires), and I don't think I've ever used 5th below 45 MPH. If I'm on level ground, I usually shift between 45 and 50. If I'm on an uphill freeway on-ramp and need to merge, I'll stay in 4th 'til I'm at cruise. You get a feel for it after a while.

As has been said, you certainly aren't going to hurt anything if you stay in 4th on the freeway. Just a waste of fuel and maybe more wear. There are times when I've come down to 4th on the freeway: If traffic slows down and we are on an uphill and I need to get going again (and get around "lesser" vehicles), I'll shift down to 4th and then back up when it's comfortable.

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Danny
'98 F-150 Std., RC, SB, 4x2, 4.2L, 5-sp, 3.08, AC, speed control, rear slider
with Syntec engine oil, MTL trans fluid, Edelbrock shocks, 50 Series Flowmaster, K&N with airbox mod, electric radiator fan

 

Bob: the discussion list is up and running: So you're the Bob I just posted to But I'll answer here too: Yes I shift into OD around about 50mph. Personally, I pay more attention to the tachometer than the speedo and to how the engine is running; lugging-down shift, high rpm's-up shift. I do prefer to be in 5th on the highway, engine doesn't have to work as hard and you get better gas milage. Of course that's up to you and you can run in 4th if you want. It sure wont "hurt" the engine.

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97F150 XLT SC 4x4 Flairside 4.6 V8 5sp Dk Toreador Red, 3.55LS
ARE tonneau cover, p255/70rx16 tires (came w/235), Superchip
Pioneer CD w/4 Polk Speakers & Clarion APA5240amp, skid plates
bed liner, side window deflectors, reese hitch, K&N air filter
40s-2chamber Flowmaster, Bosch +4 spark plugs, rustproofing
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