5.4 vs 4.6 ford engine

[Chance]

Originally Posted by JWA

Frankly I'm not willing to suggest something based upon a gamble. What works for one in their unique and specific circumstances doesn't represent a larger view of the question "which engine?".

When we're talking the newer Transit engines as compared to Modular Motors and their attendant conditions, efficiency and ratings that's apples to oranges. It in no way directly co-relates to displacement/MPG's and can't effectively be used as a comparative factor in what now constitutes different generations of engine design.

Saying larger engines automatically have lower MPG's due displacement alone is fallacy, simply not true. Computer strategies take into account the load factors and adjust fuel consumption accordingly. I'm sure a 6.8 running at 30% of its max load will use less fuel than a 4.6 at 80+%. I'm sorry but telling me a 4.6 in a loaded E350 gets better MPG's than a 5.4 or 6.8 just won't fly.

The upside to Modular Motors is across the board mechanical issues aren't much different, one not more or less prone to costly issues than the other.

Sorry, but it doesn't work that way. I was trying to disagree politely but since you decided to become aggressive with your comments I'm going to correct your errors by dealing in facts rather than opinions.

First, it's not much of a real "gamble" when Ford offered the 4.6 liter as the base engine on some Econolines, is it? Or on F-150s for years. What the hell makes a light van build that different? I get that lots of guys want 500 HP but there are plenty others who drive huge Euro vans with far less power than a 4.6 V8. It's a matter of personal choice and I stated mine, which just happens to be different than yours or that of a few others.

Second, if a 6.8 liter was working at 30 percent as you mention, a 4.6 liter with identical gearing would be working closer to 45 percent, not the 80 you throw around. And in that scenario the 4.6 would definitely use less gas. That's a fact, not just my opinion.

The question is whether either of these numbers are close to reality, so let's take a real-world look at them. In my personal case I'm using around 50 HP at 2000 RPM when cruising down the Interstate. That is approximately 130 lb-ft of torque.

It turns out that's not too far off 30 percent for my V10, making it inefficient. A 4.6 could produce 50 HP at 2000 RPM more efficiently, thereby giving me higher MPGs.

But the question was about the 5.4 V8 and the same applies but to a lesser degree. Actually, if fuel economy was a higher priority, even a 4.6 V8 is too large. To optimize fuel economy for a light build driven conservatively (as I do) we'd need an even smaller engine.

I'll gladly debate this issue with you or anyone else on an objective basis, but not if the tone of your reply is aggressive or you make it personal.


P.S. -- Also, please don't misrepresent my statements. I did not say larger engines automatically have lower MPGs.

[JWA]

Originally Posted by Chance

I'll gladly debate this issue with you or anyone else on an objective basis, but not if the tone of your reply is aggressive or you make it personal.


P.S. -- Also, please don't misrepresent my statements. I did not say larger engines automatically have lower MPGs.

It seems to me "debating" is more important than sticking to an OP's questions---my humble opinion.

Delving into topics not directly related to this OP's choices doesn't really help--I saw no mention a Transit was under consideration. If citing that is misrepresenting your comments I fail to see how.

Because OP has plans to add a pop top and occasionally pull a boat the better choice not only in MPG's but longevity of the engine itself would be the 5.4. MPG's would be in the 13-15 range plus he'd have plenty of reserve power when he van grows into something more than originally intended.

You're free to "debate" and introduce as many unrelated issues as you like but being helpful at least in my eyes is adding info particular to an OP's choices.

[E350]

Merry Christmas Men!
'Tis the season of brotherly love and good will to men.
Let's don't cannibalize our own.
At least not for someone who has only two posts.
This the reason I recently bumped Jage's "Help Vampire" thread.

viewtopic.php?f=23&t=3853&hilit=vampire

Maybe Wbp has a real question, maybe he just threw a piece of red meat out there to watch an internet flame fight among otherwise good men.
Regardless, we all respect each other and our respective contributions and perspectives and I know there will be no lasting ill will.

Now, maybe I will post a new gas vs. diesel thread...

[dhally]

This question has been asked before and it always comes down to - what do you want? These vans are expensive toys, not money-makers, and the equation is different for each owner. Sure we all would like to have good fuel economy, but realistically how many $ per year is it really going to matter?

Camper vans are more about the "lifestyle" and that includes what happens when you push the right pedal. Some like a lot of noise. Some like a lot of noise plus some smoke. Some don't mind driving in the right lane. Not many want nothing to happen - otherwise we would all be driving VW's!

[carringb]

I don't think Chance's 3.7L comparison is completely misplaced. It is used in T-series up to max GVWR which is about 11,000 pounds which is definitely E-series territory.

However.... I agree with the rest of you that smaller may not net better fuel economy. My work truck has the 3.7L (and a lumber rack) and is driven empty most of the time. With the same drive cycle as the van, I get about 11.5 MPG. Now.... if I hypermile with it locked in M6, the I can get close to 18, but I just don't like driving like that.

My dad's van has the 5.4L with 3.55 gears. Fully loaded with passengers, he still will get 17 MPG following me when I'm getting 10 MPG pulling a trailer. But, hook up the big trailer to his van, and it gets 5 MPG vs my 8 MPG because it has to cruise in 3rd (4R100) and the slightest hill drops in to 2nd.

But more importantly, the 5.4L to me feels way too underpowered. I wouldn't be happy with one in my van.

If you bought the 4.6L to save 1-2 MPGs, but didn't like how slow it was, how much would you lose on depreciation? Or lost time re-doing your conversion? Or what if it was so bad to drive on some scenic backroads, you decided to take the freeway instead? Its all subjective. What makes one person happy may not even be adequate for somebody else.

I personally recommend driving them, and making sure each motor will fit your needs before even factoring fuel economy.

[86Scotty]

Originally Posted by carringb

I personally recommend driving them, and making sure each motor will fit your needs before even factoring fuel economy.

Yep.

Looks like the OP was on last night so perhaps he's just quiet. Or amused. Or in awe. Or too drunk to type.

[E350]

Great discussion Men!
And I am sure it will be helpful to someone using the search function.
But not this Help Vampire with 2 posts and no identifiable information in his user profile who hasn't posted in this thread since Dec 14.
Again no need to cannibalize our own.
Merry Christmas Everyone!

[Chance]

Originally Posted by JWA

Avoid the 4.6 like Ebola----its a horrible engine for your anticipated use.

...cut....

Ebola? So a deadly virus is more relevant to you than the fact that Ford engineering spent millions in R&D to improve fuel economy and ended up with an even smaller engine in an even larger van?

How about EPA ratings for Econolines and F-150s which consistently rate 4.6 higher in fuel economy than 5.4?

And later 3.7 V6 rate higher than 5.0 V8 in F-150 fuel economy, given both engines at same level of technological development. You don't see the overall pattern here?

And while some swear that 4.6 V8 isn't enough for a 7000 pound van, others are fine with their 6.8 V10 pushing a 20,000 pound RV or Econoline towing a heavy trailer. Do the math and see which has more power-to-weight.

Personal preferences and expectations vary. Ours are obviously very different. I base much of mine on science and engineering, and facts over opinions. Besides, if bigger is better, why settle for a 5.4 V8 when you can get a 6.8 V10?

[derJack]

Sorry guys but its´s kind of funny to read these discussions : Several hundred horsepower are not enough to push a truck on a road that does not allow more than 65 mph.

Obviously we all love V8 and that´s why I moved to an E350. But it is also true that an engine with less cylinders and less size + turbo are more efficient. Efficient in terms of fuel. This does not necessarily mean in terms of cost! As an simple V8 Gas engine is much cheaper to maintenance and to rebuild.

Regarding the amount of power you are talking about:
To push a truck at constant speed (65 mph) on a road you surely don´t need 200 + HP/400NM. If you live in an area with lots of mountains thats different of course.
My Iveco (see avatar) was an 7000lb Truck with an 2,5l Turbo Diesel engine! This produced amazingly strong 103HP + 220NM Great engine. Very reliable and with 18mpg on the highway at 65mph. This engine was developed in the early 80ies.

So is it doable to drive a truck with 100hp /7000lb? Yes it is. Is it fun? Yes it is- if you´r not in a hurry. But as we are talking about a camper van - you will probably not have tight schedules.

[GTDad]

Great thread Guys
I think what engine size is about is balance.
Too small of an engine you will be revving higher using more gas and wearing it out sooner.
Too large for what your weight is and you will have lower revs but still use more as it is bigger and requires more just to run. But it will last longer as you are not stressing it out.
My film catering chef , my company has three identical mobile kitchen trucks about 20000lb gvw except each one has different size engine. I cant remember displacements so lets just say small medium and large.
The smallest engine truck needs more repairs and gets the worst mileage, the largest one seems bulletproof and gets decent mileage. The medium is one is u guessed it best mileage and reliable except when we have to go to some remote location with large steep hills.

The sprinters were developed for the euro cities, less hills narrow streets etc. They get away smaller engine (albeit refined) as they don't get hammered on country roads , trails etc and possibly have better aerodynamics
Think "city van"
My last camper van was b250 with a 5.2 I live in vancouver bc on the north shore mountains and frequently drive in the rockies 4+ hours at a go. The 5.2 was struggling and running hotter than I liked and mileage was low.
My current van e250 5.4 seems to do much better same route with way better mileage and runs cooler.Apples and oranges sort of..
But you see what Im getting at..