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Great Truck Engine Debate: I-6, V-6, or V-8?

Which pickup powerplant is best? Four Wheeler readers sound off on their engine of choice.

Ford Trucks and the Inline 6-Cylinder Engine

I have owned three Ford F-150s with 300ci inline-6s and 5-speeds. They were all work trucks and were fine for their intended purpose. They ran fine, had decent fuel economy, and would pull a 16-foot trailer with a '75 Jeep CJ-5 on it, at least here in the flatlands. It was common for me to haul 3- and 4-cylinder Deutz diesel engines back and forth to the repair shop. I put a lot of highway miles on them and was looking for trucks with low repair costs. I never had a driveline failure on any of them, and most repairs were due to wear or road hazards. During the time that I owned these trucks, I also had two F-150s with 351s and automatic transmissions. I still have one of them, a '95 that I bought new and still drive. The only major repair has been to replace the rear axle bearings. It's still on the original ball joints and exhaust. Of the three work trucks, I sold one because I no longer needed it, parked one when the body mounts rusted out, and retired the last one in 2014, when I retired. I don't have any experience with the newer V-6s, and I doubt that I would buy a fullsize pickup with a 4-cylinder engine, but I was very happy with my inline-6s.
Bill Giles
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Inline 6-Cylinder Engine or V-6?

Ah, yes, the venerable Ford 300 I-6. My father started a career as a heavy-equipment mechanic at the end of the 1970s and to this day still works on old, industrial iron. Back in the early 1990s, he was employed by a company that serviced forklifts and other material-handling equipment. He had to carry about a ton of tools and equipment onboard his work truck 24/7 and had to occasionally tow a trailer with equipment on it, as well. Which truck did his company give him? Well, as you mentioned in your October '19 issue (Firing Order), it was a different time back then, and trucks were viewed as tools. The truck they gave him for this task was a brand-new '92 Ford F-150. It was regular cab, longbed 4x2, with manual trans and the 300ci I-6, and A/C was the only option. The company purchased that truck for around $10,500 new. It was woefully underrated for the work he was doing, but that's what the company fleet manager said he was going to use.

So, my father put 100,000 abusive miles on that truck in 36 months. He ended up having to install overload leaf springs in the rear because the factory 1/2-ton suspension wasn't happy with the 2,000 pounds of tools plus the loaded equipment trailers he pulled. The clutch fluid reservoir also had to be topped off weekly because presumably the slave cylinder was starting to die. But otherwise, that truck never complained and served its duty day in and day out for three hard years.

In 1995, the company finally decided to replace his truck, and they bought him a new F-250 XL with the 5.8L V-8 and automatic trans. You would think this to have been a massive upgrade, but the new truck drank gasoline like it was sponsored by OPEC and still ran to redline any time a slight incline popped up. I think Dad missed the old straight-6. He purchased that old '92 F-150 from the company for $3,500 and gave it to me for my 16th birthday. I proceeded to put another 30,000 miles on the old straight-6, pulling a tractor, hauling rock, and even driving the truck to college when I moved away. It never gave me the first problem or sign of a hiccup. I wish I had a photo of that truck somewhere.

I think it's true that the general public views anything less than a V-8 to be insufficient these days. That's because trucks are no longer viewed as simply tools for a job. But I also feel that the old I-6 engines were far more reliable than any V-6 offered today. I mean, just look at the poor track record of Ford's new EcoBoost engine family or the valvetrain failures on Ram's Pentastar engine. I do believe that times are different now, and in order to get the 300ci I-6 level of reliability, you do have to purchase a V-8 if you're buying a new truck in 2020.
Shawn Crowe
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The Inline-6 Keeps Going

I enjoyed your article on straight-6 engines. Some of us never had a choice—stock Toyota FJ40 owners! I like the engine for the torque at very low rpm.

I bought my FJ40 used in 1990 and once lugged the engine through a snowfield at about 400 rpm—it chugged like an old tractor but never stalled. In 2013, my daughter had a learner's permit and minimal experience with a manual transmission. I let her drive up Argentine Pass in Colorado on a Rising Sun 4WD Club trip, and we ran into milk-crate-size boulders after a switchback. I told her to floor the gas and don't touch the clutch. The torque of the 2F blitzed through these boulders with the truck bouncing wildly, and we made it to the top of the pass. She was thrilled, and I was thrilled to still be alive. What I have disliked on hot days is having the carburetor right over the exhaust manifold, but throttle-body injection cured that and added more power and drivability. So, I hope to lug my engine and truck forward many more years with its stone-age technology—and loads of low-end torque.
Steve Helmreich
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Inline-6 Flashback

Was reading your story about 4- and 6-cylinders in fullsize trucks. Growing up, we had the same truck: an '80 Ford F-350 2WD, 300ci I-6 with granny 4-speed, dark brown with white/beige cab. Manual everything, no A/C. We drove cross-country in it twice. I learned to drive in this truck. My dad got it from his dad, and he still has it on our ranch in Oregon. I'm 33 now, and I remember having that truck since I was about 6. Thanks for the stroll down memory lane.
Kyle Endicott
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Old Iron for the Win

My first truck in high school in 1984 was a '70 Dodge 1/2-ton two-wheel drive with a slant-6 and three on the tree. I once tried to pull a small camping trailer with it, and it couldn't do it. I ended up leaving the trailer on the side of the road and having someone else come get it. The first new truck I bought was an '89 Nissan Hardbody with a 4-cylinder and 5-speed. It got lousy fuel mileage for a small truck; I soon regretted not buying a fullsize Chevy with a V-8 that got comparable fuel economy and only cost a little more. After a few years, I bought a used '90 Chevy work truck with a V-6 and 5-speed, and that was also a disappointment. It had no power and got the same fuel economy as a V-8 truck. I traded that work truck for an '89 Chevy shortbox 4x4 with a 5.0L automatic. I loved that truck—it got good fuel economy, had decent power, and was reliable. My son still drives that truck to work every day in Nome, Alaska. My current motor pool of pickups is an '89 Chevy Suburban 1/2-ton that has a military 6.2L diesel with Banks turbo, intake, and exhaust kit. It is a great truck and gets decent fuel economy. The M37 is a 1953 that I bought two and a half decades ago in original condition with its flathead-6. I drove it with the 6 for a year but got tired of people on the road being frustrated with its slow pace, so I installed a 6.2L diesel and ran that for a decade or so. A couple years ago I swapped it for a 454 and wish I had gone with the 454 in the first place.

I don't have any interest in new vehicles, so I won't be buying any, but I am aware that the new small engines are getting pretty amazing performance out of small packages. A guy I work with drove a Ford F-150 EcoBoost for a few years, and he was impressed with its power. I would have to be able to disable all the electronic gadgetry like auto start-stop and cylinder deactivation. I just can't embrace all the new BS. I want to drive my truck; I don't want it to drive me and tell me what it thinks I should be doing. I am happy with my old reliable V-8 trucks.
Cecil Ramsey
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