PSD gets around 16mpg back and forth to town....V-10 gets 12mpg if you keep your foot out of it. Same gears on both trucks. I've pulled an enclosed trailer that is 20 ft long and has cargo of about 7,000lbs on the flats of Kansas and in the Rockies and get between 7.5 and 9.5mpg out of over-drive with the V-10.

 

I think the gears are 3.73s and gets great mileage as long as he keeps it under 70mph. He says if he goes higher than that the mileage suffers. It just makes sense to me that the taller the gear the more fuel your going to burn because the engine turns faster,

I think this is true up to a point. I am thinking about switching from 3.73 to 4.30 gears to increase mileage. My thinking is along these lines. Pulling a load at around 65 miles in 4th gear is like 1900 rpm, to accelerate at from that rpm takes a lot of gas or a down shift which would bring the engine up to around 2700 rpm. In either case minor fluctuations in speed take a lot of gas to accomplish. 4.30 gears woud bring the 65 mph rpm up to around 2100 where there is a bit more power available. This would equate to less downshifting and movement of the throttle to adjust speed and hopefully lower mileage.

 

I think that mileage will vary depaending on what you do with your truck. If you just drive it to work and back during the week and occationally pull a holiday trailer on the weekend, 3.73 gears are fine, they will give good mileage and still decent puling power for a trailer. If you pull trailer all the time then yes go for 4.11s or 4.30s as those gears will be easier on the powertrain overall and may get you more mpg. On my 79 f250, I have 4.56s but I have 40" monster mudders, I never pull trailer with it and get 17mpg highway. I guess it boils down to what you do with your vehicle the most and set it up accordingly.

79 f250 460 c6 40" rubber 4x4
99 explorer 4.0 sohc
89 f150 302 5spd 4x4

 

I thought the V-10 was a small block (basically a 5.4 with 2 cyls tacked on)?

 

It's neither a "big-block" nor a "small-block", neither of which really describes any Ford motor. It's a "modular". Period.

FE's can be called "big blocks", but even that's a misnomer.

What's a 429/460? It's physically smaller than a "big block" FE, but at a max of 460 cubes (or bigger), it's no "small" block.

heh heh

 

OK Krewat, like the header says, now you've done it, I have been wanting to ask someone this forever, and then some. Exactly WHAT is the difference between a big block and a small block, besides the obvious of course, which really aint all that obvious if you start looking at it. GM had a 350 small block, and a 350 big block (actually a destroked 400 Pontiac?). Ford had the 351 Windsor which was a small block ? And the 351 Cleveland which is a big block ? So obviously the size of the block would dictate big block/small block, but HOW ? I saw a 427 small block Vette, which was a LS6 punched out, and GM had the 396/ 427 & 454 big block. So what gives, what is the determing factor in big block versus small block ? There has to be some sort of factor, doesn't there ? Anyone know ? Thanks so much.

 

My truck with the 4.30's gets 11-12 city and 14-16 hwy.

 

There is no specific distinction in cubic inches for what is a small or big block. Traditionaly car manufacturers have had multiple familys of engines, each with their own evolutionary process. Tipicaly one is larger, and one is smaller. For GM the small block has been the 327 305 350 which all use the same heads and manifolds with minor differences. This is refered to by GM owners as the small block. GM big block is the 396 427 454 again with a lot of common parts. Ford has done things a little differently with several variations of engines. again at any given time one is smaller and one is larger. 289 302 small block 390 460 big block, with a few others in between.

Demads to meet emission regulations have forced ford into developing the modular motor, with more cylinders to make more power. it is easier to control combustion in a smal cylinder vice a large one so by limiting size of the cylinder there is little to do other than add more cylinders to increase power. The end result is a 415 cubic inch motor that makes good power on modern low octane fuel. The Modular motors were specificly designed for this purpose. Dodge on the other hand just added two cylinders to their 360 and made their v10 that way. The Dodge V10 is a rather crude motor compared to the Ford Triton

If you want to call a V10 a small block based on common parts with with the 5.4 V8 go for it. But it no longer applies because there is no larger block to compqare it to.

 

Im pretty sure the 460 is heavier then a 390.its definetly wider thats why they couldnt use a 429 in a mustang til 71'.With the exception of the boss 429 whaich the shoch towers had to be modified to fit.

 

You are probably right. I saw a 460 ONCE. Nestled into a late 60's Fairlane that came with a 289/302. The FE throws you off because of the huge intake that extends under the valve covers... makes it look bigger than it is.

I always thought that compared to an FE, the 460 was a lighter way to go (and cheaper, until recently). Another assumption bites the dust...

However, I did once measure a 360 to see if it would fit into a Triumph TR7. Amazingly, it would... I needed that 4x4 oil pan though

thanks!

 

Okay, so almost 24 hours late on this...
Best I can get is about 14, 12 around town.
geraldv mentions "makes good power on modern low octane fuel". On my recent trip west, I came across two things I have questions about:
1. Across IL and Iowa, they were selling ethanol laced mid grade gas, and selling it cheaper than the non-laced 87 (regular). For those that have run ethanol, any long-term problems? It seemed to run fine for the few tanks I put through mine.
2. Once we got out to South Dakota, I started seeing a lot of "regular" unleaded at 85 Octane. How can they run that crap through their vehicles? I know that around here, Sunoco tried to lure customers in with a better "price" posted, and when you got to the pump, it was 86 octane. I only ever ran one tank of that, and the valve ping was enough to drive you nuts. Are they doing something out west different that allows the use of 85 octane in engines other than lawn mowers?
Thanks, just curious.

 

I do a lot of driving in Baja Mexico and the gas they sell down there is poor at best. My old ford truck with a 351W would ping and knock like crazy, but my v10 has no problems at all. I can't say for sure what he octane rating is, but I would bet it is 85 or less.

 

I realized that. I was just messing with you (and all the other diesel owners out there. )

 

SteveMc,
The ethanol-containing fuel will be just fine for you vehicle. It's completely safe for modern vehicles. I live in Iowa and I've filled up with 89 octane with ethanol for the past 5 years because it's cheaper than the 87.
The main reason they use it is to develop a larger market for corn crops since Iowa produces so much of it. (Ethanol can be derived from corn).

 

So what IS the difference between big block and small block ? There has to be something ? A guy can have a 427 small block, a guy can have a 350 big block, so it's not cubic inches, so what is it ? Surely with all the brilliant minds that hang out here while not solving the worlds problems someone can explain this to an old country boy ? I've been asking this question for 35 years, and never had anyone who could really give me a definitive answer, but there has to be some parameter that defines big and small. Is it bore spread ? Is it overall crank length ? It has to be something, what ?