Towing speed?! How fast are you........

**bertschb** · 01-07-2021, 10:08 AM

Originally Posted by Skijobe

I didn’t know Ford had a 7.3 Diesel. I had one on my 2002 F-250. My 2020 F-350 is a 6.7 diesel.

The new Ford 7.3 is a gas engine.

**WhittleBurner** · 01-07-2021, 03:59 PM

Originally Posted by Skijobe

I didn’t know Ford had a 7.3 Diesel. I had one on my 2002 F-250. My 2020 F-350 is a 6.7 diesel.

The 7.3 diesel engine Ford had ran from 1999 to the second half of 2003 when they went to the 6.0. That 7.3 was and is a very good engine. There are people that still have them and will not give them up.

**powerscol** · 01-07-2021, 04:19 PM

Originally Posted by WhittleBurner

The 7.3 diesel engine Ford had ran from 1999 to the second half of 2003 when they went to the 6.0. That 7.3 was and is a very good engine. There are people that still have them and will not give them up.

I also had one. The weak link was the cam position sensor. Owners new to keep a spare in the glove box with a 17MM socket. When it failed the truck just shut down - no warning. A 3 minute change out and you were good to go. I now have an 04 6.0 (lemoned an 03 6.0) Last your my 6.0 melted the EGR cooler 6K later and back in business.

Looking at the new 2021 6.7 models or may wait for the 2022 refresh.

Now to really confuse things Ford has a new GAS 7.3. Its called the Godzilla motor.

**LawDawg** · 01-08-2021, 03:10 PM

A little math to consider......

First, the stopping power required is related to your kinetic energy as you move down the road. The formula is KE = 1/2 m v^2. You'll notice that the velocity is squared. Hence the difference between the stopping power required for two speeds is not a straight line on a graph but looks more like a logarithmic curve. For example, you need 36.11 percent more stopping power for 70 mph than you do for 60 mph (and that's assuming a perfect world where your brakes didn't heat up al all during the stop and you didn't break traction and move from static friction to dynamic friction!).

Second, gas mileage differences are also more significant than we might think. Wind resistance increases in the same way as kinetic energy (with the velocity being squared -- see https://en.wikipedia.org/wiki/Drag_(physics) ). Truckstop.com says "a truck traveling at 65 mph will experience a fuel efficiency increase of about 27% compared to a truck traveling at 75 mph" and further that "speeds over 60 mph are greater in fuel economy loss than time savings" for commercial operators.

FWIW I set my cruise at 65 mph unless there are safety issues which suggest slower or (temporarily) faster. ;-)

**Calnca** · 01-08-2021, 03:23 PM

What most don't consider is the "abuse" the unit got before you ever saw it.

I44 &I40 Westbound, you'll see all the delivery contractors hauling new units from the manufacturer to Western dealers......frequently see them in the 75/80 range blowing by me at my pokey 65....granted they are really light compared to our fully equipped unit, but you need to understand the tires have already been "tuned" up for you by the delivery contractor.

**Gregmisc** · 01-09-2021, 05:28 AM

Originally Posted by Skijobe

I didn’t know Ford had a 7.3 Diesel. I had one on my 2002 F-250. My 2020 F-350 is a 6.7 diesel.

Oops, my mistake. I have a 6.7 diesel.

**Have Griff Will Travel** · 01-12-2021, 07:33 AM

I'm retired so I don't see a need to get anywhere in a hurry. I try to keep my speed at around 60mph and enjoy the sights.

**Crazybanshee** · 01-12-2021, 07:47 PM

I run the speed limit up to 75 MPH. Have the Goodyear G614's on the trailer.

**That 1 Ron** · 01-20-2021, 03:20 PM

Originally Posted by WhittleBurner

The 7.3 diesel engine Ford had ran from 1999 to the second half of 2003 when they went to the 6.0. That 7.3 was and is a very good engine. There are people that still have them and will not give them up.

Actually, the “powerstroke” 7.3L diesel (direct injection, Navistar built) was used in 1994.5 HD trucks to very early 2003 SD trucks. It went through a few minor updates, the biggest being the 1999 super duty which added an intercooler, electric lift pump, split shot injection, bigger fan/radiator, and the upgraded 4R100 automatic (very similar to the previous E40D) and the upgraded 6-speed manual transmission. Ford also offered the 7.3 diesel ( indirect injection) as far back as 1988. I believe only the 1993-94 trucks were available with a turbo though.
These really only share the bore and stroke with the “power stroke” 7.3 engine.

**That 1 Ron** · 01-20-2021, 03:26 PM

Back on topic, 65 mph max towing unless I really need to pass someone. I also used to be one of those guys who would put the hammer down but after some close calls and tire failures (fortunately, only with heavy duty flatbed trailers) I have changed my driving habits. My Tundra will go as fast as I dare but really 55-60 is the sweet spot. So 65 on the freeways, if conditions permit, and usually 5 mph under the speed limit on the other roads.