5.4 vs 4.6 ford engine

[Wbp]

Well this has been very interesting more information then I expected. and yes I am new to the forum and I am just starting to work on this project and have found lots of great idea and views on this forum but could not find anything on this question. Thanks for all the information it is very helpful to see all the different views and try and figure out what fits my plans. I am sure I will have more questions and hope that I get more great views from you guys.

[JWA]

Wbp's opening post wherein he's seeking specific info about the 4.6 vs 5.4 motors---I replied directly to that.

Originally Posted by Chance

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?

The pattern I see is dumping superfluous info about engines soooo NOT covered by Wbp's query. Citing science and engineering aspects might serve general conversations but regadless how interesting it still doesn't contribute much to the info or experience being sought.

As to facts over opinions sorry guy but science and engineering are only opinions especially as it relates to direct, in-hand or on-the-road experience with a specific engine. Trying to sway someone with published facts as opposed to relating personal experiences from those operating the specific engine choices adds nothing to the conversation. IF OP isn't considering a Transit or its engine choices then "debating" the merits thereof aren't helpful.

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.

Originally Posted by Chance

Besides, if bigger is better, why settle for a 5.4 V8 when you can get a 6.8 V10?

Well because when my current E250 was purchased as new-to-me a V10 couldn't be found. Throwing that same question back if smaller is more efficient then why are you driving a V10? Huh?

Wbp if this isn't helpful its surely entertaining right?

BTW guys---Merry Christmas to all!!

[86Scotty]

Merry Christmas to you too JWA! It sure has been entertaining and glad the OP is entertained and not run off by our bickering. Since reading this I've been thinking about how one's engine size is synonymous with one's wealth. It you have a 7.3, 6.0 diesel or V10, you are RICH! You've got plenty to spare! It's super easy to say "I could live with less" but you don't and maybe you never have, so how do you really know? And if you do know, then why don't you? Whereas if you're 'poor' and live with a V6 or small V8 in a big vehicle you think "If I only had more I would be happy", but then when you get it it's usually never enough and you want more, more, MORE! This is not at all a shot at Chance, who's input I appreciate, but it is a statement about the grass always being greener. At the pump or the repair shop, the big engine guys think "I could live with less, then I wouldn't have this burden", and when the small engine owners are trying to climb a hill on the interstate and can't get out of their own way their only thought is "If I only had more, I'm loooooossssiiiinnnnnggggg!" Personally, the latter sentiment, which I've felt more often than not in my automotive live, well, SUCKS! I don't care what numbers say on any vehicle. I have to drive it, in many circumstances, not just a quick road test.

[Chance]

Originally Posted by 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.

....cut.....

I agree but will add that for the "balance" you refer to to have value it has to be evaluated or compared in similar context. Without similar context conclusions can be misleading.

As an example, I can follow your small, medium, and large engine experiences when applied to 20,000 pound trucks, but how does that actually compare to the question at hand?

The largest gasoline truck engine I'm personally aware of was just under 9 liters in size. However, they are rare and now old so it's likely you are referring to engines in the 8-liter size or smaller at best.

Given that a light camper van as mentioned in the OP could be roughly 1/3 the mass of your mobile kitchen trucks, then it follows that a 4.6 liter engine is proportionally even larger than any possible large engine in your trucks. And by a wide margin. So if your largest engine is bulletproof and gets decent mileage solely due to its large size, then a 4.6 should be fine in that it's even larger compared to the van's size and mass.

[dhally]

Originally Posted by Wbp

... could not find anything on this question....

Try entering something like "ford 4.6 liter site:www.sportsmobileforum.com" into Google and you can find more threads:

http://www.sportsmobileforum.com/vie...p?f=39&t=10792
http://www.sportsmobileforum.com/vie...p?f=34&t=14530
http://www.sportsmobileforum.com/vie...14409&start=15

[Chance]

Originally Posted by 86Scotty

.....cut....... This is not at all a shot at Chance, who's input I appreciate, but it is a statement about the grass always being greener. At the pump or the repair shop, the big engine guys think "I could live with less, then I wouldn't have this burden", and when the small engine owners are trying to climb a hill on the interstate and can't get out of their own way their only thought is "If I only had more, I'm loooooossssiiiinnnnnggggg!" Personally, the latter sentiment, which I've felt more often than not in my automotive live, well, SUCKS! I don't care what numbers say on any vehicle. I have to drive it, in many circumstances, not just a quick road test.

You make a great point about unrealistic expectations. Before I purchased my E-350 with V10 years ago, I rented an F-150 with 4.6L and towed a travel trailer over 2000 miles on vacation. The steepest Interstate grades I encountered as well as a couple of tall bridges were handled by dropping out of OD. More power would have been OK but hardly necessary for me. I didn't even need 2nd gear -- drive was plenty.

That trip convinced my wife and me that trailers alone were not for us (OK if camper van doing the pulling), so when I got back I started looking for a lightly used 15 passenger window van. Based on that experience I wanted a 5.4 because it was the smallest available engine in a 15-passenger wagon (as far as I knew), but couldn't find a good one. I also wanted 3.55 gears but the van I liked had 3.73.

The F-150 with 4.6 V8 and trailer combination was heavier and far less aerodynamic than an Econoline van, so I'm still certain that would have been my engine choice if only available. I could have gone with E-250 and 4.6 but my wife wanted a "finished" window van. Since then I briefly looked at engine swap to downsize but at +/- 15 % MPG improvement there isn't enough savings to justify cost. Fuel economy really isn't that big a deal -- especially at today's fuel costs.

Anyway, I don't mind polite disagreement one bit, so it's not a shot at me in any way.

Merry Christmas to all.

[GTDad]

Originally Posted by Chance

I agree but will add that for the "balance" you refer to to have value it has to be evaluated or compared in similar context. Without similar context conclusions can be misleading.

As an example, I can follow your small, medium, and large engine experiences when applied to 20,000 pound trucks, but how does that actually compare to the question at hand?

The largest gasoline truck engine I'm personally aware of was just under 9 liters in size. However, they are rare and now old so it's likely you are referring to engines in the 8-liter size or smaller at best

Given that a light camper van as mentioned in the OP could be roughly 1/3 the mass of your mobile kitchen trucks, then it follows that a 4.6 liter engine is proportionally even larger than any possible large engine in your trucks. And by a wide margin. So if your largest engine is bulletproof and gets decent mileage solely due to its large size, then a 4.6 should be fine in that it's even larger compared to the van's size and mass.

I guess i was getting at is "fit"
What fits your needs and situation. If you live somewhere somewhat flat I can see a 4.6 might be just fine.
But if you live somewhere with a lot of mountain driving it might not.
Bigger engines don't have to be driven as hard so theoretically should last longer.
The Kitchen trucks I speak of often go into remote and unusual places with steep hills even the truck with the "largest engine still crawls at walking speed up some these hills.
That is some serious engine and drivetrain stress.

As I understand engines will get best mileage and efficiency in narrow power band.

I had always thought westy's got better mileage than a bigger domestic van until I researched online and compared notes with friends with westy's
Smaller engine revving way higher- less efficient and more breakdowns.
This I saw myself when road tripping down to socal a few times from vancouver bc. I saw lots of Canadian plated VW's Westies parked at garages along the way.
Or broken down at San Onofre beach on one occasion, got to give guy credit he had coveralls and his big tool box and was taking his engine apart right in the parking lot..
And his family with hime including a 6 month old.

[Chance]

Originally Posted by GTDad

.....cut.....

As I understand engines will get best mileage and efficiency in narrow power band.

.....cut.....

In my opinion, based both on technical data and personal experience, it's not as narrow a "power" band as is often reported.

If we look at a Brake Specific Fuel Consumption map for a typical gasoline engine, most can produce significantly different amounts of power while maintaining a high level of efficiency. The trick is that load (as in Brake Mean Effective Pressure which is like torque adjusted for engine size) has to be controlled by using the correct engine speed or gearing. On the internet we often read that engine speed has to be reduced in order to improve fuel economy but this should be viewed as a means to an end rather than the end itself. With older American vehicles that had large engines and or low gearing, reducing engine speed through new gearing (like added over drives) helped but it was mostly because it increased torque and hence BMEP. With some newer vehicles that start out with smaller engines, trying to gear them too high to lower RPMs may actually waste fuel. You have to get it just right.

In my opinion, the bottom line is that it's easier for a smaller engine to produce more power while maintaining a high level of efficiency, than it's for an oversize engine to run efficiently at low loads. As a rough example this means to me that a 4.6 may get 16 MPG in overdrive while running solo, and maybe 11 MPG while towing a trailer without using OD. In both cases the engine is running efficiently at different power levels.

On the other hand if one starts with an oversized engine for the need (like my V10 for a smaller van) it's nearly impossible to gear it high enough to run as efficiently when not towing. While towing it can do as well because it can run at lower RPMs.

Contrary to popular assumptions, there isn't that much BSFC difference between a 4.6 V8 at 3000 RPM, and a 6.8 V10 at 2000 RPM. On the other hand a 4.6 at 1800 RPM at 60 MPH may feel much better than a 6.8 at 1200 RPM -- assuming it could even be geared that high for cruising at around 60 MPH. When we need less power it gets to the point that smaller engines make more sense.

Numbers don't lie if applied correctly. For towing or large heavy rigs big engines can do as well as smaller engines. For low loads associated with smaller rigs large engines waste fuel. They may provide other benefits like additional power, but they waste fuel nonetheless.

[GTDad]

Well said chance:
I don't need a v10 for my 2wd e250 5.4 but I would not want a 4.6 for driving in the mountains where I go a lot.
Ie The TV show "highway to hell" =Coquihalla Highway in BC

[E350]

I remember that road...
My wife and I drove it at night in our 2002 7.3L PSD in February 2010 from Whistler to Revelstoke.
(Before winding our way back down to Radium and Fairmont hot springs and Kicking Horse (!!!) Fernie, Red Mountain, Big Red Cats and Whitewater.)
Although the van weighed ~9,600 lbs. on that 26-day trip, we had no problems with power.
However, the Flames and Oilers driving 18-wheelers back presumably to Calgary were relentless and I pulled over scared on the ice caked road many times to let their bow wave shake my van as they passed at speeds which I thought were over-limit in Canada. Eh?