Does anybody make a 4WD truck with 'good' MPG?

[mayhem]

I guess most pickup owners are more concerned about low-end power than highway mileage? My 4 banger sucks at both ends, in any case. I have no low end to spare even though my truck spends 95% of its time on the highway. At 70mph I'm over 3000RPM in 5th gear, but it's about maxed out power wise.

My Silverado is for around town, the commute, heavy, big or rough loads and plowing. Its got a 6.0 gas motor and 4.10 gears so its got alot of get up and go at the stoplight, pulls heavy loads very nicely...but it drink gas like Dean Martin drank martinis and on the highway the 4.10's keep the motor well over 3000 rpm most of the time...pushing it to 80 makes me feel like I'm abusing it, while my wife's Audi is just getting warmed up at 80 and wants more.

If we need to go anywhere as a familyand we don't need to carry big heavy stuff we take the A4...its more comfortable and gets nearly double the mileage. If I've got something heavy to do I've got the right tool for the job.

 

[Abner]

most modern engines will get worse mpg with 3.23 3.73 etc gears even the silverado(been there) If emmisions were not so strrict we could have engines that made power at low rpm and could turn low gears efficently modern engines make the best power at high rpm It comes from the epa being more worrid about what comes out the tail pipe rather than how much goes in the tank.

I have a 1983 4x4 s10 with plow with 3.73 gears that I get 20 mpg but the way I have it set and running the epa would have a fit. but it does like e85 too

 

[Abner]

the gearing also makes the bigger engine get better mpg alot of times(if driven properly)
you are using 90% of the 4cyl's power to move the truck at 3000 rpm
but only 40% of the 6cly's power at 2500 rpm with lower gears

 

[saichele]

It's funny - probably part of our preference to 'tax' the vehicles not the gas. Europe has looser emissions and fuel requirements, but gas is 2x or 3x more, so people use less. Less goes in the tank, less comes out the pipe. Here, we constrict the motor and exhaust, essentially overbuilding the engine so we can lose efficiency on emissions equipment. So we pay thousands more on the upfront cost, but half or a third as much for the fuel.

Steve

 

[KeithO]

Many vehicles get poorer mileage in 5th gear than 4th gear simply because the power required to drive the vehicle at that speed requires a greater throttle opening (a higher manifold pressure) at the low RPM. The vehicle manufacturers have to balance many things, including economy, the ability to carry rated load and passenger comfort (low engine speed = quieter).

If the engine technology is comparable, a smaller engine will always get better mileage than a bigger one. The only exception to this rule is when running the small engine absolutely flat out all the time, since the engine management system will richen the mixture to keep temperatures under control (use the fuel as "coolant"). This is one of the reasons why the Germans do not get good emissions on the autobahn, since every gas engine is overfueling at 130mph to stop the valves and pistons melting. This same principle has been used since the 30's in aircraft engines in takeoff conditions to get the last possible HP out of the engine with having it do the "hand grenade" trick..

The bigger engine, running at part load to produce the same HP as a smaller one will have a higher manifold vacum (lower pressure) which results in the engine having to do more work to suck that air mixture into the cylinders. This is what is referred to as "pumping losses". If the throttle on the smaller motor is almost fully open, the pumping losses are much smaller. The most efficient operating point for any gas engine is with the throttle fully open and at the peak torque RPM where the flow characteristics of the motor are best. Thats not to say it is the best operating point for the vehicle, since drag increases at the square of the speed hence cruise speed tends to be below peak torque RPM (unless its Ok to drive 100mph).

Then you have to consider that the bigger motor is heavier, its transmission is heavier, the axle is heavier, the chassis / body have to be heavier to manage all that extra hp. The gas tank is bigger and if filled to the same % it will be heavier with fuel too. So weight is against you all the way with bigger engines. Every time you have to accelerate that mass, you are burning extra fuel. Each time you brake, you convert that inertia into heat. Stop and go is obviously the worst case scenario.

It should thus be no surprise that some of the most fuel efficient "conventional" cars are light weight and have small motors with preferably a manual transmission. They will generally have skinny tires too, for low rolling resistance. Those V8's dont sell with skinny tires last time I looked. The tires alone can have a 5-10% fuel penalty on fuel consumption.

Emissions technology has not changed significantly for gas vehicles in several years. There has been a focus on total emissions, including evaporation from the fuel tank etc. Recently there has been a focus to reduce NOx emissions (created at high combustion temperatures, particularly when running lean) but this impacts the diesel segment much more than gas engines.

 

[Abner]

NOx emmisions are huge part of gas engines there are 2 ways that they are cut first with the EGR system to lower combustiion temps(a proper EGR helps fuel economy by effectivly making your engine smaller at light loads) the second way that NOx is reduced is lower compression ratios to cut combustion temps and this is where mpg goes. the engines of today are around 2-4 points lower compression then in the 60s and 70s

I am not supporting pollution, but I do think that we have gone about it completely wrong

give me a modern engine with 10.5 -11.5 compression and fill it with good fuel or e85 and you will get better mileage than anything comparable


the bigger engine will not get less economy due to the surounding vehicle unless you are comparing a 2.0L 4 cyl to a 8.1L big block then yes you will have heavier components with it

example 200? K1500 silverado 4x4 ext cab - 4.3v6 4.8v8 5.3v8 and in high end packages 6.0v8 all using same transmision the 4l60e the same brakes same axles same fuel tank
the 5.3 will get better economy especialy(sp) with a load

same with a 200? ranger 2.3?i4 3.0v6 4.0v6 same drive train different engine

pumping loss is a valid argument but that is also adressed with the egr system

 

[Firewoodguy.com]

The wife has finally broken me. She does not want to over-winter with my beloved '82 Datsun KingCab 4WD truck. It has the rust cancer pretty bad, and can be a bit finicky. So I am looking for a new truck. 4WD is a must to get to our place in winter. I prefer manual transmission.

Problem is, all of the trucks I have seen, Toyota Tacoma, Nissan Frontier, Big4, etc, have what I consider very poor MPG ratings. Only Toyota makes a 4cyl 4WD - and it is only rated at 19/23 (2007 EPA). That is pathetic! The Nissan Frontier is 6cyl (they do not offer 4cyl in 4WD) and is 17/21. And none of the trucks available are really 'compact' anymore. What has happened to the 'small' truck market?

These MPG's seems very poor to me, and I can't find much other choice. I prefer to buy new, because I plan to keep this thing for quite a while. Also, I have found it very difficult to find Manual Transmission models on the lot. Nissan only made 14% of their Frontiers in 2007 with the Manual Trans.

Advice or comments?

Try the Hummer, I get close to 11 MPH on my 2006. I think thats a excellent MPH for a 4WD.

 

[KeithO]

The EPA revised the way the fuel economy ratings are measured in the field and averaged. Expect to see worse numbers for new models of your favorite big V8 trucks too. Toyota just had the luck that the Tacoma is a new model in 2007 and thus has to comply with the new EPA fuel economy rules. The imbalance one would presently see is only temporary until all vehicles have been re-rated. Once that process is through, you may find that the Tacoma don't look so bad anymore.

In 3-5 years time, when gas is $5/gal, the EPA may have to revise their test procedure again, since US drivers may have developed a lighter right foot after all the pain in the wallet at the pumps. This recent change reflects the fact that the average US driver accelerates much harder than initially estimated by the EPA when they first set up the economy ratings. The goal of the revision is to more accurately portray the kind of mileage attainable by an average driver with an average driving style.

So if you drive like a tenderfoot, you may in future get mileage better than the EPA estimates, where in the past, they actually assumed you were a tenderfoot....

 

[drizler]

You couldn't give me a 2 WD truck in snow country. They are just the worst thing ever made for sliding around, period. One thing the Europeans have figured out is how to count to 6. Just like the amp on that spoof movie "This is spinal tap" their transmissions go all the way to 6. Wow if only we dumbass continentals could figure out how to shift that high. I have managed it and even driven both a 5 and 6 speed interchangeably on the same day. What an accomplishment eh. It amazes me they make a car with a 2 litre engine that will toss you in the back seat like a GTO, run happily all day at 125 and get 36 MPG. Why oh why can't we develop the technology to make a car like that. Funny the Krauts just don't have any pick up trucks at all. About all I see is the occasional silverado and a few of the imports but damned few. Strangely in the 70's when the VW pickup diesel was all over the US I never saw even 1 over there anywhere, just vans.

 

[KeithO]

No pick ups because it is such a wet climate. Sometimes go 5-6 weeks at a stretch with rain every day (not all day, but you get the idea). They do have nice vans though, the MB Sprinter is just one of many. The Sprinter will get 28mpg day in and day out while hauling a load and keeping it dry.

 

[timfromohio]

Six is good, but eleven is better. The amps in "Spinal Tap" go to eleven. Eleven man ... that's the ticket ...

 

[colsmith]

Evidently I don't understand the need for a 4WD, although certain friends tell me they need one. I live in WI. If it snows too much, we just stay home. They always plow the roads in a reasonable amount of time, it is only my driveway that can be a problem when we haven't shovelled well or it drifts a lot. We are on our third Ford Ranger, all 2WD. Actually we still have the second one, it is 17 years old and has 209,000 miles. It just passed its emissions test today, what a relief. We ruled out the 4WDs since their mileage is noticeable worse. What are the conditions that you regularly encounter that require a 4WD? Driving off road, or lots of snow and a long driveway, or ?

We stick with the Ranger extended cab since hubby (6'7") fits in it well and doesn't fit in most other vehicles well, and we have a recurring need for a pickup truck. Now especially with the wood hauling, but we schlepp a lot of manure, wood chips, boxes of produce and other crud as well. Our old truck got about 21 mpg and we are supposed to get about 24 mpg with this one, but I don't think we have kept track enough to be sure about that. The current ones are automatics, the first one was a stick shift. It is hard to find manual transmissions these days, we buy used so it makes it harder. Our car gets 50 mpg, it is a tiny hybrid, that is what we drive when not having to carry anything big.

 

[Bill]

Some people need 4x4 and some don't. I have a need and use it during the summer moving my boat, pulling it out of the launch etc. I have a very long and steep gravel driveway that requires 4x4 to back up to turn around. When the boats on the trailer you can not back up the driveway. I use the 4x4 every week. I am considering getting chains also. My atv is 4x4 and I have gotten it stuck in the driveway last winter. So I have chains for it also. The biggest problem with chains, they are hard on mag wheels. For long trips I use my economy car, but for boating the truck is the only way to go for me.

 

[mayhem]

I couldn't plow my driveway without engaging 4wd...unless I did it every half inch of snowfall.

I also don't necessarily have the option of staying in if its snowing. Anything less than a foot of snow I'm going into work.