gen1 ford superduty and max radius turn

[John in Santa Cruz]

our Tacoma (access cab, standard 6' bed) can pull the E21 with a standard size towbar at a full stop U turn going forward without touching. looking at a 2002 F250 diesel 4x4, 6.5' bed, extended ('super') cab, wondering if that will be OK on said full stop turn? apparently this specific truck has a 52' turning circle (OUCH!), I believe the Tacoma 4x4 AC has a 40' circle.

[Brian B-P]

Originally Posted by John in Santa Cruz

our Tacoma (access cab, standard 6' bed) can pull the E21 with a standard size towbar at a full stop U turn going forward without touching. looking at a 2002 F250 diesel 4x4, 6.5' bed, extended ('super') cab, wondering if that will be OK on said full stop turn? apparently this specific truck has a 52' turning circle (OUCH!), I believe the Tacoma 4x4 AC has a 40' circle.

Toyota Tacoma Access Cab w/ 6' box:

• wheelbase = 127.8" (10.65 feet)
• track = 63" (5.25 feet)
• With the Tacoma's outside front tire running around a circle with 20-foot radius, the outer rear tire will be running on a circle with 16.9 foot radius, so the middle of the axle will be on a 14.3 foot radius.

Ford F-250 SuperCab w/ 6.5' box:

• wheelbase = 141.8" (11.81 feet)
• track = 68" (5.67 feet) - this is a guess, based on similar trucks, since I didn't find the track for this specific truck
• With the F-250's outside front tire running around a circle with 26-foot radius, the outer rear tire will be running on a circle with 23.2 foot radius, so the middle of the axle will be on a 20.3 foot radius.

With the F250 turning on a significantly larger radius, the angle between truck and trailer (given that it's the same trailer) will be less (closer to straight) than with the Tacoma... so, no problem.

This ignores the relatively small effect of different rear overhang, and assumes that the ball is a similar distance behind the bumper, to allow space for stuff overhanging the sides of the trailer tongue to clear the bumper.

[Iowa Dave]

It is surprising sometimes to get in a vehicle that’s not that large and then experience a big turning radius with it. I had a 94 Dodge Dakota, huge radius for a small rig, probably only made about 25 U Turns with it the whole time I owned it. Got like my hero Broderick Crawford on three point turns. The Highlander feels pretty good.
Iowa Dave

[Brian B-P]

Originally Posted by Iowa Dave

It is surprising sometimes to get in a vehicle that’s not that large and then experience a big turning radius with it.

During a trip I asked for a rental car that had a hatchback (for something I had to carry) and was given an Isuzu Rodeo, which was a compact SUV sharing a chassis with a pickup truck. The first surprise was how astoundingly bad it was on the first highway ramp (made my parents' station wagons feel like race cars), but the bigger surprise was that it made a 3-point turn for a reasonable vehicle into a 7-point turn. I was very happy to trade that thing for a minivan later in the trip.

I have heard explanations that this is due to the 4WD: the front wheels can't steer as tightly because they have driven axle shafts. That's not true, because every front-wheel-drive car I've driven (including our van, which is longer than the Rodeo and so should have a larger turning radius) turns tighter than this thing. The problem is likely the traditional U-joints used, instead of modern CV joints.

In this example, the F-250's turning circle should be larger than the Tacoma's due to the F-250's longer wheelbase, but only by 11% (not 30%). It would seem likely that the F-250 has U-joints and the Tacoma has CV joints, and that appears to be the case in a quick web search.

[Donna D.]

I had a huge eye opener when I bought my 2014 Ford F-150... the turning radius was HUGE compared to my 2000 Ford F-150. WTF! Thankfully I drove to a parking lot and did some tests. But boy... was I disappointed.... felt like I was turning a barge compared to my earlier truck. Sigh.

[John in Santa Cruz]

re: turning radius, my last two daily driver cars were a 1992 Volvo 740 wagon, with a 32' foot turning circle, and a 1993 Mercedes 300CE convertible, with a 36 foot curb to curb turning circle, so all these trucks feel like boats by comparison, still the Tacoma 4x4 doing 40 feet curb to curb isn't bad. The Volvo was ludicrous how tight you could turn, heh.

[John in Santa Cruz]

Originally Posted by Donna D.

I had a huge eye opener when I bought my 2014 Ford F-150... the turning radius was HUGE compared to my 2000 Ford F-150. WTF! Thankfully I drove to a parking lot and did some tests. But boy... was I disappointed.... felt like I was turning a barge compared to my earlier truck. Sigh.

was the '14 a 4x4 and the 00 a 2x4 ? 4x4 definitely complicates things as the drive shafts to the front wheel constrain the turn angles.

[Brian B-P]

Front axle joints can constrain turn angles, especially if they're U-joints. It looks like the 2002 SuperDuty has U-joints in the front axle, but both 2000 and 2014 F-150's have CV joints.

Another factor is wheelbase, which varies substantially among trucks even of the same model. The turning circle diameter goes up essentially in proportion to the wheelbase, for the same steering angle; it's the geometry of similar triangles.

• The turning circle diameter for a 2000 F-150 varies from 40.49 feet to 51.25 feet, again due only to wheelbase (from 119.9" to 157.4").
• The turning circle diameter for a 2014 F-150 varies from 41.7 feet to 52.3 feet, due only to wheelbase (from 125.9" to 163.1").
• The turning circle diameter for a 2002 F-250 4X2 varies from 48.25 feet to 58.35 feet, due only to wheelbase (from 137.0" to 172.4").
• The turning circle diameter for a 2002 F-250 4X4 varies from 50.44 feet to 61.61 feet, due only to wheelbase (from 137.0" to 172.4").

Turning circle diameter can be from curb-to-curb or wall-to-wall. Since recent data is only for curb-to-curb, all of the above values are for curb-to-curb.

The 2000 and 2014 F-150 have virtually the same turning circle, for a comparable wheelbase. Over the years, there has been a tendency for pickups to come in ever-longer combinations of cab and box sizes, and a tendency for people to choose the longer cabs. As a result the trucks turn wider due to configuration choice, not design.

In the case of both years (2000 and 2014) of the F-150 the turning circle is the same regardless of 2WD or 4WD. This might mean that the CV joint angles are not the constraint; it might mean that the truck was designed for 4WD steering angles, with clearances to inner fenders and other components to suit, and so the 2WD version can't take advantage of potentially tighter steering angles.

In the case of the 2002 F-250, 4WD increases the turning circle diameter, by a couple of feet. It seems likely to me that the U-joints in the front axle are constraining the steering angle.

[Donna D.]

Originally Posted by John in Santa Cruz

was the '14 a 4x4 and the 00 a 2x4 ? 4x4 definitely complicates things as the drive shafts to the front wheel constrain the turn angles.

That's exactly the condition. I didn't realize it was going to make such a difference. But places I could do a U-turn in the 2000, I certainly can't with the 2014.

[Brian B-P]

Originally Posted by Donna D.

That's exactly the condition. I didn't realize it was going to make such a difference. But places I could do a U-turn in the 2000, I certainly can't with the 2014.

Since 2WD versus 4WD makes no difference to turning circle diameter in these F-150's... what were the wheelbases (or cab and box configurations) of the two trucks?

[Donna D.]

I don't remember much about the 2000, but it was a Supercab just like the 2014. The 2014 has a wheelbase of 145 inches. Both had/have a 6.5 box. Too, the 2000 had 16" tires and the 2014 has 17" tires.

[Brian B-P]

Originally Posted by Donna D.

I don't remember much about the 2000, but it was a Supercab just like the 2014. The 2014 has a wheelbase of 145 inches. Both had/have a 6.5 box.

In both years the SuperCab came in two box lengths with corresponding wheelbases. For the 2000 F-150 that's 139" for the 6.5' box (and 157" for the 8' box); the 2014 with SuperCab and 6.5' box has a 144.5" wheelbase (and there's a 8' box and 163.1" wheelbase). Donna, your turning circle diameter has gone from 45.9' to 47.0'. Well... a foot can make a difference.

Also, Ford published wall-to-wall diameter (in addition to curb-to-curb) for the 2000, but not for 2014. The 2014 likely has a bulkier body, so there would be more difference in the wall-to-wall numbers... and if you're trying to clear walls or posts or other vehicles, it's wall-to-wall that matters.

Originally Posted by Donna D.

Too, the 2000 had 16" tires and the 2014 has 17" tires.

The wheel diameter doesn't affect turning circle diameter, but the tire width does affect the curb-to-curb diameter (slightly). The published specs will all likely be for the base tires; wider tires could add a couple of inches.