Back in February, Ford announced a new, 7.3-liter gasoline V8 engine for the 2020 Ford Super Duty. It was light on the details then, but no matter, because we have them now.
Today, Ford announced that the 7.3-liter engine, available first in the Super Duty F-250 and F-350 pickups, will be good for 430 horsepower and 475 lb-ft of torque, according to a company press release.
And there will also be a “dyno-certified” version of the V8 that will make 350 HP and 468 lb-ft of torque that will come standard on the F-450 chassis cab, F-550, F-600, F-650 and F-750 Medium Duty trucks and F-53 and F-59 stripped chassis models.
If you were a little underwhelmed by the power output of the big motor, don’t worry because we were, too.
David Tracy and I put our heads together and made a few predictions as to why the modest output. Firstly, and likely most importantly, the motor is probably designed with a focus on achieving lots of low-end torque more so than on spitting out crazy amounts of power. This type of thing tends to be preferred for towing and hauling. Plus, as a truck motor and not a performance car motor, this thing may be built with heavy-duty components that don’t want to rev as high.
Second, we guessed when you have a high displacement but a relatively low maximum power and torque output, it could mean less stress on the engine thanks in part to a lower compression ratio. This could mean better longevity under high load.
Third, compared to a downsized and turbocharged motor, the big, naturally aspirated V8 likely offers a favorable torque delivery behavior and over-simplicity. There may be some serviceability benefits over a boosted unit, as well.
But let’s not forget the less technical benefits of a large motor: There are probably a lot of Ford truck fans out there that would absolutely relish the opportunity to tell the forums all about their 7.3-liter V8s.
David called Dr. Andy Randolph of ECR Engines (you’ll remember him as a NASCAR engine expert), who pretty much agreed with our guesses.
“With average lighter load as far as what the engine could potentially do, temperatures go down, pressures go down, wear of all the components go down,” he said. “When you boost an engine, you’re increasing the internal pressures and temperatures... you’re working the engine really hard.”
The motor, he supposed, is likely “biased to a very low speed” and he believes Ford probably “[sacrificed] those peak figures in order to get those low speed figures. Those low speed torque figures are the key to having something that feels good when you [tow].”
He also pointed out that low speeds and high loads are operating points where engine knock can become an issue. This motor could have a lower compression ratio, which would help there, especially when regular-grade fuel is used.
“It’s just tailored around very low speed torque and low speed performance,” Randolph told us. “In a truck, you want something that will have good drive-ability when you’re towing these big loads.”
What’s also curious is that Ram offers in its heavy duty Rams a 6.4-liter V8 naturally aspirated gas motor that’s good for 410 HP and 429 lb-ft of torque. Those figures are lower than the Ford’s, sure, but Dodge also has a 6.4-liter Hemi naturally aspirated gasoline engine in the Charger 392 that makes 485 HP and 475 lb-ft of torque (The Charger has a significantly higher compression ratio, if you were curious).
That’s way more power and torque than the heavy duty Ram or even the much larger Ford motor. So, it seems like gasoline heavy duty truck engines aren’t actually known to be the kings of peak power and torque when compared to vehicles with engines of similar or even lower displacement.
Therefore, while for a 7.3-liter V8, 430 horsepower and 475 lb-ft of torque doesn’t seem great, in the heavy-duty truck world, where low-end torque and longevity under high loads are key, it’s a bit of a different ballgame.
When asked about the power, a Ford spokesperson responded, “The focus for the 7.3-liter was total capability as delivered in vehicle. We have class-leading peak torque, but we valued capability from 1,500 rpm on up over obtaining an even larger advertised peak torque. All versions of the 7.3-liter are capable of delivering over 400 ft-lbs from 1,500 rpm on up. We believe this large amount of torque from low engine speeds is exactly what a heavily loaded vehicle needs for good drivability.”