trucks-V6 or V8

[john blanchard]

Looking at new trucks for an Idea of prices for when i get home later this year, a big difference betweem 6 0r 8 cylinders, 4.3 L V-6 OHV MPI 195 hp @ 4,600 RPM 260 ft-lbs @ 2,800 RPM engine, 4.8 L V-8 OHV SMPI 285 hp @ 5,200 RPM 295 ft-lbs @ 4,000 RPM engine. Big difference in hp but not in torque. The 6 starts at 19G, the 8 at 29G, is the V8 worth the extra 10G, I'll be doing cabinets and stair cases, hardwood floors, hauling materials, maybe a small trailer, is the V6 capable or will I drive it into the ground trying to keep up in traffic.

[Dave Fifield]

Hi John,

Horsepower = (Torque x RPM)/5252, so in order to compare apples to apples, you really have to compare engines at the same RPM's. Actually, it's best to have a complete torque vs. RPM curve for each engine (good luck finding a copy though!). HP is not usually measured, it's calculated. Dynos measure torque. Torque is what you "feel" as a driver. HP is not really a very useful measure of performance.

For good hauling power, you want to make lots of torque at all RPM's, but especially, you want the engine to be able to deliver high torque at high RPM to take advantage of gearing. You want a torque vs. RPM curve that doesn't top out and drop off at high RPM.

Comparing the 6-cyl and 8-cyl engines you are looking at, the V8 will accelerate to speed MUCH faster than the V6. The V6 presumably max's out its torque curve with 260 ft-lbs @ 2,800 RPM (manufacturers usually quote the peak torque). The V8's peak torque is 295 ft-lbs @ 4,000 RPM. So it has a much wider torque curve than the V6, resulting in a much improved driving experience.

With a big load, the V6 will be a relative slug on the road compared to the V8. It will still be nice to drive though.

For comparison, I have a 2001 GMC Sierra K-3500 with 8' bed and large crew cab. It's a monster, but its 7.4 litre V8 purrs - it produces 330 ft-lbs of torque @ 2,800 RPM. With no load, it accelerates like any other car on the road. With a load, it has always done me proud.

I think you need to test drive them both (uphill/with a load if possible) and see if you prefer the extra oomph that the V8 gives you is something you want/need. I don't think we can tell you if the extra 10G is worth it - you will have to make that decision yourself.

Good luck! Let us know which one you choose.

Cheers,

[Joe Chritz]

As stated above...

Unless you plan on hauling a large load either is probably fine.

If you plan on hauling a load then you need power. I am a diesel fan if you have large trailers to haul.

Remember to figure what the majoity of you driving will be and plan for that. Also check on insurance rates, in some vehicles there are several hundred dollars difference in rates between engines.

Enjoy

Joe

[David G Baker]

Looking at new trucks for an Idea of prices for when i get home later this year, a big difference betweem 6 0r 8 cylinders, 4.3 L V-6 OHV MPI 195 hp @ 4,600 RPM 260 ft-lbs @ 2,800 RPM engine, 4.8 L V-8 OHV SMPI 285 hp @ 5,200 RPM 295 ft-lbs @ 4,000 RPM engine. Big difference in hp but not in torque. The 6 starts at 19G, the 8 at 29G, is the V8 worth the extra 10G, I'll be doing cabinets and stair cases, hardwood floors, hauling materials, maybe a small trailer, is the V6 capable or will I drive it into the ground trying to keep up in traffic.
6 cylinder Cummings diesel or 8 cylinder for gas is what I would do if I was in the market for a new truck and I wasn't trying to compete with a tractor trailer rig.
David B

[Al Willits]

Another thing to look at is, are you in a hurry?
I had a neighbor who would pull a RV trailer to Texas each year with a older Chevy 1/2 ton PU with a straight six in it, 50-55 mph the whole way.
That'd drive me nuts, but it worked for him.

Look and see what engine rpm these things cruise at, used to have a 3/4 ton Ford with a 302 carb'd engine that would tow my fishing boat, either out of the overdrive, and at a fairly high rpm range at 60 or so speeds, or in OD and at 80+mph to keep it in its best power band.
Neither worked well.

Both will pull a small trailer, just depends on at what speed you want to go, find the one that has most of its torque at the speed your comfortable with. imho
Al

[Charles McKinley]

Do you need a truck or a car with a really big trunk? If you are going to be working it there is no replacement for cubic inches. If you will rarely if ever need to load it to the max GVW the V6 will be more engine than you will ever need.

[Joe Pelonio]

My 2007 Ranger 4.0 liter V6 is 207 horsepower and is rated to tow 6,000 lbs. I have moved a lot of heavy furniture and power tools in it since I got it, moving my business and helping my son move, and it's got plenty of zip.

This is a great time to buy a new vehicle, the dealers are desperate for sales.

[Frankie Hunt]

My FIL has a Dodge Dakota with a v6 that gets poor fuel mileage. (17ish) I have a couple of firiends who have full sized Chevys with V8s that get better fuel mileage (20ish) and have more power, more room, more hauling capacity.

My past trucks, all bought new, were: 1987 f150 4x4 with 300 in-line 6, manual transmission. It would haul anything I needed, got decent fuel mileage, but didnt have enough "umph" for my taste. (On a 2 lane road you couldn't pass very well. Uphill on-ramps were not always a pleasant experience) I swore my next truck would be a V8 with auto transmission. Well.... My next one was a 1994 f150 4x4 with 300 in-line 6 manual transmission. Same story with power and mpg. Duh.... In 2004 I traded for an f250 with 6.0 diesel, automatic transmission 4x4. Wow..... I increased my mpg to 22 (if i drive gently) and now have TONS of pep and power. I swear this truck feels as peppy as a 94 5.0 liter mustang I used to have. I couldnt be happer. If you want to go, just mash the pedal, want to go fast, just press a little farther down, regardless of the load. Traffic is heaver now than 20 years ago. I feel much better about getting in the thick of things having excess power vs being underpowered.

[Rob Russell]

For good hauling power, you want to make lots of torque at all RPM's, but especially, you want the engine to be able to deliver high torque at high RPM to take advantage of gearing. You want a torque vs. RPM curve that doesn't top out and drop off at high RPM.

Comparing the 6-cyl and 8-cyl engines you are looking at, the V8 will accelerate to speed MUCH faster than the V6. The V6 presumably max's out its torque curve with 260 ft-lbs @ 2,800 RPM (manufacturers usually quote the peak torque). The V8's peak torque is 295 ft-lbs @ 4,000 RPM. So it has a much wider torque curve than the V6, resulting in a much improved driving experience.


Dave,

I have to strongly disagree with your post.

It's my understanding that you want torque at low RPMs because that's what you use to overcome inertia and get a load moving. That's why diesels are so good for hauling - they make gobs of torque at low RPM. You want HP to keep the load moving or to sustain momentum. That's why the big trucks slow down on hills - they don't have the HP to keep the load moving and torque doesn't do anything at high RPMs.

For around town driving, especially with a load, I'd rather have a torquey V6 that makes its peak torque at lower RPM than a V8 that makes its torque at higher RPM.

Rob

[Jason Roehl]

Rob and Dave, I disagree with you both. :D

I think Rob's right in that you want torque at low RPM to get a load moving. Dave's right in that you want torque at highway RPM to keep a load moving. At speed, your truck is overcoming various frictional forces (rolling and air), which the torque needs to overcome. Horsepower is essentially a measure of how quickly the torque "recovers"--a measure of work, which is force applied over a period of time. Torque is an instantaneous measure of rotational force. With a breaker bar and a long cheater pipe on that, I could apply 1000 ft-lbs of torque to the rear wheel of a truck by hand, but it's such low horsepower that I would never get the truck moving very fast.

What you ideally want is a flat torque curve--which is where diesels excel. A Cummins diesel I6 in a Dodge gets 90% of its peak torque at idle--that's about as good as it gets (it would actually peak much higher but has to be limited to spare the driveline). My BIL worked (as a mech. eng. in testing/design/bldg. management) on the Dodge/Cummins diesels up until about '03 or '04. Smaller engines in large vehicles compensate by revving higher (able to do so with less rotating mass) and using lower (numerically higher) gearing. While this gets the job done, it increases wear. Motorcycles that go 65mph @ 5000 RPM don't last nearly as long as a 14L I6 in a semi that cruises that speed at 1500 RPM.

Personally, I think a V6 in a full-sized truck or van is a total waste--BTDT. Entrance ramps to the freeway become a dangerous crapshoot and you're constantly downshifting to get up small hills. Even that 4.8L V8 you're looking at will leave you short from time to time. I suspect that the $10k difference you're seeing is much, much more than the engine option. $19k for a full-size truck would be a very stripped down model, whereas you can get a pretty nice setup for $29k. A close friend just got an '06 crew-cab F150 last fall with the 5.4L V8 for $25k, almost all options except 4x4.

[Jason Roehl]

Oh, yeah, here's a pretty good explanation of torque and HP:

http://science.howstuffworks.com/fpte.htm

[john blanchard]

Thanks for responces, My price is in canadian $, the 19G truck did not have many extras at all, very plain.

[Rob Russell]

Polite debate - gotta love it! :D

[Dave Fifield]

You guys! :D

[Jim Bell]

I have a 2004 F150 Super Crew Lariat. Curb weight is 6100 lbs. I get 16-17 mpg in town and 20 or so on the hiway. It has the 5.4 engine. I have several friends with similar trucks with V 6s and V8s. The fuel mileage is very similar driving empty. Put a 5000 lb trailer behind them and the 5.4 beats them all. I am in the process of adding a cold air kit and dual exhaust. The hype is 25-50 HP increase and an additional 2-4 mpg with these units installed. I am also dropping the front of the truck 2" and the rear 3". That should be good for another 1 mpg.I am also changing the automatic ATF to Amsoil. The engine will be using 0-30 synthetic and the rear end will use 75-90 WT gear oil, also synthetic Amsoil. If you mat the throttle you will notice a decline in fuel economy but the response is good. I wish you the best.

[Cary Falk]

10G for a V8 upgrade sounds high. It sounds more like you are compairing a mini truck to a full size. I agree with Jason that a V6 in a full size truck is a waste. I also think a 4 banger in a small truck is a waste. I had a V6 in my S10 and now have a V8 in my tundra. I don't regret either engine choice. Resale value will be bigger with the bigger engine.

[Norm St.Onge]

I drag a trailer around almost daily; either a 6x10 tool trailer or a 14ft dump trailer with a tractor loaded on (or a pile of new material or a pile of job site debris). If you're going to be hauling 'stuff' on a consistent basis go with the bigger engine.

My area is very hilly, lots of gravel roads and not many passing zones. So if I'm stuck behind a car and all I can see is a tuft of blue hair and boney knuckles on the steering wheel I need the oomph to safely pass grandma when the opportunity arises or I could spend a looooong time on the road.

I went with a Dodge 2500, it tows like a dream and has power left over to accelerate at will. The down side is fuel economy; 9-11mpg when towing. Ugh. But, I need it and factor those costs into my billing. A diesel would have been nice but for an extra $6k on the bottom line I couldn't justify it.

-Norm

[Ken Kimbrell]

I’ll not try to debate which truck is best because it all depends on just what you‘re trying to do and what you can afford, plus your brand preference makes a big difference... mine has always been Chevy, but as you'll see below Dodge has won me over.


After having all kinds throughout the years (from the 60’s till now) I like the one currently in use better than any of the others… that includes small ones like an early 60’s Datsun that would only haul few hundred pounds to newer ones like a 2000 Dodge Dakota with v6-gas/auto and lots of others of various sizes and engines and body types, including Fords & Chevy’s.


For me the 2500 Dodge with a Cummings is the only way to go… the one you see in this picture works for me very well and so far no job has been too big for it to handle.


Ps: That's 6 tons of freshly cut lumber you see on the trailer.
See more pics here (http://www.mykimbrell.com/Tons-O-Lumber.htm)