Watch out, he's polishing his calculator....

 

The sad part is thats the only way he can prove it, Real world tests never work out like they do on paper!

 

True, but he's pretty cool about it...

GO CHARGERS!!

 

Funny thing happened to me today. I was parked at the exit from gas station and suddenly could hear high-pitch engine noise. Turned around ready to see one of those Kawasaki bikes, that run 12,000 rpm, but saw a pretty big motorhome instead.
Obviously V10 powered.

 

Yes, thats what it means.

If they both have the same load on the same hill, and the 6.7 is making 400 and the 3.5 is making 415 it will pull harder.

 

Are you forgetting Bill, that diesel engine is going to have about double the torque of the gasoline one?
The HP/torque issue is pretty tricky one and not so easy to understand.
To add to confusion the manufacturers data stinks most of the time.
For example I remember generation old fact.
If Japanese car is rated 30 mpg you can expect 32-34.
If US car is rated 30 mpg you'll be happy exceeding 25.

 

Whoever made the comment was saying that putting the hemi and the 6.2 in the same sentence was not good for the 6.2. I was saying that just because they share the same number of spark plugs does not mean they have anything in common performance wise. Like a psd and a jetta. They burn the same fuel, but do you see a jetta towing 15-20k lbs?

When I said HP is all that matters we were talking about comparing two engines with the same gearing at the same rpm. The one that has more hp at the given rpm is going to pull more weight. Like comparing a v10 to a 6.4 at 2,000 rpm(once you factor gearing into it and turning different rpms, hp doesn't matter much and engine tq doesn't matter at all). I was not saying whichever engine has more peak hp will pull more weight. There is more to it than peak hp. It's like comparing my 4 cyl turbo coupe to my old stock 5.0 mustang. The mustang has more peak hp and more peak engine tq, but the 4 cylinder would out run it in the 1/4 mile all day long because it had a lot more power across the entire powerband than the mustang did. If you let the v6 run at peak hp and the 6.7 run at peak hp, the v6 will pull just as much weight. It will be 2 gears lower and turning twice the rpms, but it will still do it. But as far as getting a load moving, it won't even be close if they have the same gearing.


So me comparing two trucks pulling the same trailers on the same hills with the same driver and seeing which one pulls better doesn't count?

Engine tq only matters if you are comparing them in the same gear at the same rpm because the one with more tq has more hp and more tractive force. Once you factor gearing into the equation, engine torque means nothing. My 7.3 has more engine tq than my 5.4, but my 5.4 can run a gear (or two) lower and multiply the tq to the ground and actually put a lot more power to the ground.

 

Yes I do. Well. ... almost

 

They Lost...

 

I drive for ups and we found the same thing. They junked the first set of them that where about 10years old and had around 200-250 on them and they where completely falling apart. Big rear end and transmission issues as well as motor.

Btw on topic ups has been buying alot of new gas motors for fear of maintnance cost of the newer diesels

That said the new trucks are coming in with 6.7cummins/allison-frieghtliners. Internationals (nit sure the motor but sounds like the old 444 internationals we have). And workhorses that have the big gm motor 8.1 iirc

On topic the longest running trucks we have are the old gm gas 6cyl from mid eighties. The 97fords are being scraped because the maintnqnce is so expensive while the 25year old gas gm's are still on the road they just get a new motor every 200-300k miles.

 

Fellas, I am impressed. I normally read the thread in it's entirety before I post anything, but quite frankly, I could finish the Bible faster. So here I go.

1) In answer to the original question (way back on page 1) it ultimately comes down to the expected use. If you will regularly haul heavy loads and/or trailers then the PSD would be a superior engine, because over the life of the vehicle, you'd probably be dollars ahead from a fuel cost standpoint, despite the higher initial cost. However, if you are only occasionally pulling a heavy load, and mostly running empty or driving something else, (I.E. you tow a boat or an RV a few weekends here and there) I just don't think the diesel makes fiscal sense. I am a certified diesel nut, but i also have to be realistic. Especially the way modern diesels are, I probably would go gas. I have all kinds of certifications to work on gas and diesel vehicles. That might by why I am driving a 1993 Suburban (Diesel) and a 1996 F-150 (gas 4.9L). I just don't want to spend the money, and then even more money for special equipment so I can work on my own stuff. As for real trucks not having spark plugs? Well all I can say about that is there must have been no real trucks until the late 1950s then. All those deuce and a halfs that landed on Normandy and helped free Europe in WWII must have been a bunch of poser trucks. That's like all the folks who tell me my truck "ain't no real truck 'cause it ain't got no V8 under the hood". Because so many class 8 rigs run V8s right? No pitiful inline sixes under those hoods, huh?

2) High RPM Horsepower Vs Low RPM Torque:

If truck "A" is capable of producing 400 HP at 3,500 RPM, and truck "B" is capable of making 400 HP at 6,000 RPM, then if each truck is geared correctly (and we know that the factory always does that right ) they should both be able to pull the same weight at the same speed. So assuming they have the same transmissions, if truck "A" has 3.73:1 final gearing, and truck "B" has 6.39:1 final gearing, there would be no difference.






















Say what? They don't offer 6.39:1 gearing as an option? Well then the low RPM engine will pull better than the high RPM engine. Or the low RPM engine could be re-geared to 2.99:1 (assuming the high rpm engine was able to be geared 5.13:1) to achieve the same results.

 

So does any gasser at this altitude....(I'm torn between what I consider my Hometown Team (Chargers) and The Seahawks when I was in 2nd Bat)

 

I know that UPS is still running allot of trucks equipped with the 300 Ford / NP-435 combination still. There are several in Harrington DE, near where I live. I have had the opportunity to see under the hood of a few that are still used daily from that hub, because I have a relative and a friend who both work there. They of course (like the Chevy 292 SM465 combination) are the least expensive to operate despite fuel economy and are the most reliable.

 

Good point, and I can't offer any rebuttal to that from sea level Delaware. Besides, my diesel is normally aspirated, so it would struggle as much as any normally aspirated gas engine.

 

This first part is what gets so many on the gasser side riled up. Saying that it is only good for occasional towing or driving empty. I will (and do) pull anything with my 5.4 that I would pull with my 7.3. The only difference is the rpms they turn going up hills.

You are saying the same thing the gasser side is saying here. That if both are making the same power, with different final drive ratios, they will be going the same speed and capable of towing the same load up the hill.

They don't offer a 6.39 rear end, but they do offer a transmission that changes gears. So, say you have your psd with a 3.73 rear end and a 1.0 tranny gear, you have a 3.73 final drive ratio. Now say I am in my gasser with a 4.10 rear end and I am in a tranny gear of 1.60. That gives me a final drive ratio of 6.56.