The Future Of The Manual Transmission

qbrozen

so are you in neutral when getting that 300mpg reading?

I have NO idea how much a car uses at idle. However, 0.2 gph seems low to me (again, without any real knowledge on the subject), as that means a car with a 15 gal tank could sit there and idle for more than 3 days straight on a tank? :confuse:

stever

UPS says up to a gallon an hour (quoting an EPA study).

"UPS drivers adhere to a no-idling policy to help reduce fuel consumption and harmful emissions. UPS has cut the amount of time delivery vehicles idle by 24 minutes per driver per day – a fuel savings of $188 per driver in one year."

Saving Fuel: The Benefits of No Idling

kyfdx

UPS driver makes $250/day.... and, they are saving $0.75/day, paying attention to how much they are idling...

I wonder how much the industrial engineers make that figure this stuff out.... and what the timeline is for that payoff?

Because if turning off that truck adds more than 2 minutes to the driver's day, then they are losing money....

plekto

The math is easy on that one.

24 minutes times 200 days worked, divided by 60 minutes is 80 hours a year.
$188 divided by 80 is $2.35 per hour. This is a too coincidentally exact number, so if you do some quick math, you get a $3.35 a gallon price figure and a 0.7gph estimated use. (most large trucks and semis range from 0.7-0.8 idling) This seems right for what is probably 1-2 year old raw data.

BUT - that's for a large diesel engine. Most of these are P500-800 series vans that are customized for UPS. Almost all of them have a Cummins 6.7 diesel engine in them. A smaller gasoline engine should get much better than 0.7 gph idling, even if they are less efficient at doing so.

A typical gas engine is 25% efficient while idling, and a typical diesel is about 40%. Taking that into account, a 6.7L gas engine should use 1.6X the fuel of the same diesel engine while idling. That's 1.12gph Or about that's listed in most magazines. But if you plug in displacement of, say, a 1.4L engine like in the Cruze, you get a 0.23 gph figure, give or take. Most engines with a 3.0L or so engine will, of course, use almost 0.5 per hour, with a slight difference in use do to idle rpms. (almost all gas engines idle at 650-800 rpm for smog purposes, no matter what the displacement)

dudleyr

Yes I am in neutral when getting 300 mpg. The scanguage has different limits than the built in car computers so I do not get a reading of infinity ever. My mpg also does not go up when I shift into gear while going down a steep hill. It stays the same and then slowly gets worse as the engine drag slows me down.

I will look at my scanguage today to see what it actually reads during idle. Yes .2 gph does seem low, but the numbers I saw ranged from about .15 to .5 depending on engine size and efficiency. I suspect my Accord is just over .2, but I will get the actual reading off of the OBDII computer.

ruking1

Having been used to do that kind of work (not in shipping and logistics although I came out of that back ground in a former work life) , I can tell you they will not release the results of those various studies to the general public.

stickguy

Guy I know just bought a new Buick regal turbo. With the manual tranny. So take heart, they sold at least 1 of them this year!

ruking1

So how are you liking it so far? Also what sub vendor (if any) does the 6 speed transmission?

ateixeira

Just a SWAG - Getrag?

ruking1

That would have been on my list of guesses also. Funny even the latest articles don't nail it down 2011 Buick Regal Turbo-6 speed manual Aisin to GM's "own"

stickguy

not mine. guy that lives near me.

nippononly

There's hope! Geez, I hope that's not the only Regal Turbo manual they sell this year!

ateixeira

It's a European car, basically, so it's not as surprising as it seems.

dudleyr

Just checked gallons per hour on my Accord with the Scanguage. About .7 gph when the engine is cold and at fast idle. Once warm it is at .3 gph when I first shift into neutral then after about 10 seconds goes down to .2 gph. Since it does not register hundredths all I can say is .24 gph or less when fully warmed up.

shipo

Makes complete sense. Question: what is the GPH when warm and in Drive?

plekto

This also backs up my rough "napkin math" previously. Since most cars these days are using smaller and smaller engines, it's really displacement that determines how little fuel it uses idling. A figure of 0.25-0.3 isn't unreasonable these days.

note - a very small direct injection engine might actually get by with cycling every other piston stroke's fuel. I suspect that 2 cylinders running (for smoothness/balance) would be more than enough to keep it turning over.

EDIT - also, displacement seems to be the largest determiner of highway MPG, as most cars today run about the same RPM ranges in overdrive. (roughly 1600-2000 at 65mph). A small 2.0L I6 (as an example) would probably give you 35-40 mpg highway and still get you around pretty quickly.

ateixeira

as most cars today run about the same RPM ranges in overdrive. (roughly 1600-2000 at 65mph)

Not in my experience.

At 2000rpm my Miata is doing about 42mph.

That's in 6th gear, BTW. At 65 it's over 3000rpm.

colin_l

Almost no 4-cylinder vehicle is as low as 1600-2000 at 65mph, whether naturally aspirated or forced induction.

All v8s are in that range and some v6s are as well, especially higher output v6s.

This topic is interesting, albeit misnamed.

volkov

Prior research by National Resources Canada yielded this equation as a mean calculation:

Idle Fuel Consumption Rate per hour(L)= 0.350 x (engine size in L) + 0.330

So for an average 3.0L engine, that would be about 1.38L or .37G per hour.
Muddying the waters is that this data is from 2005 iirc, and changes to compression, cylinder cut and DI will alter those numbers. I'd be willing to guess that a 2011 3.5L sedan sees the same idle number as its 2000 3.0L counterpart did.

Part of my son's science fair experiment last year. :-)

qbrozen

EDIT - also, displacement seems to be the largest determiner of highway MPG, as most cars today run about the same RPM ranges in overdrive. (roughly 1600-2000 at 65mph). A small 2.0L I6 (as an example) would probably give you 35-40 mpg highway and still get you around pretty quickly.

Well, contradictory to that, I have a 2.0L engine... and it does not get anywhere near 35 mpg highway.

plekto

Note that I said a 2.0L I6. The idea is extremely low revs at highway speeds out of a very small engine. The extra cylinders are there to give it all enough torque to be drivable. The 4 cylinder equivalent would be a supercharger or turbocharger added onto it, which is what GM and Ford are trying now (and what modern diesel engines have been doing for well over a decade now)

Mercedes made some 2.2 and 2.3L I6 engines back in the 60s, IIRC, and they got very good fuel economy for their time.

shipo

"Note that I said a 2.0L I6. The idea is extremely low revs at highway speeds out of a very small engine. The extra cylinders are there to give it all enough torque to be drivable."

Hmmm, all else being equal (which it rarely is), it would seem to me that a long-stroke I4 of two liters in displacement would have more torque than a relatively short-stoke I6 of two liters in displacement. Yes, no?
:confuse:

colin_l

Completely agree. I don't think he's on a technically accurate path at all.

Since hardly anyone makes small displacement six cylinders in cars or trucks, this is more easily seen comparing small displacement motorcycles and ATVs. There it is obvious and compelling... fewer cylinders for a given displacement is more torque, more cylinders is less torque but very often more horsepower.

There's also the matter of cost and packaging efficiency to explain why we don't see any 2.0L inline sixes.

oregonboy

At least, not recently:

qbrozen

right. mine is a 2.0 turbo ... so it has much more torque than a 2.0 I6 would have ... yet runs quite high revs on the highway. However, per the instantaneous readout, I can tell you that, at 2000 rpms in 6th, which is something like 50-55 mph, it still won't net 35mpg.

There is much more to efficiency than displacement.

plekto

Well, if the turbo is still operating at highway speeds, that's a design problem. Also, some engines are just simply not designed very well. My dad's Buick at 50-55mph is running at a whopping 1300rpm.

Its top gear is a real overdrive, which helps as well. (the rest of the car is, well, a big Buick...)

kyfdx

It's easy with an automatic.... no matter how low the revs or torque, a downshift is one ankle flex away.. With a stick, most engineers are going to leave a little extra... because who wants to shift out of top gear, every time they go from 60-75 mph?

Plus, qbrozen drives a GTI.. I wouldn't say that engine isn't designed well... It's just not designed for maximum highway fuel mileage.... :P

plekto

True...

I drive stick as well, and keep the revs at around 3000 at all times. Yeah, MPG isn't the best, but I might as well enjoy it while it lasts.

ruking1

Wow ! On one 4 banger, if I did 3,000 rpm (5th gear/5) I'd be cooking along at between 95-100 mph.

kyfdx

Diesels don't count.... :shades:

plekto

Well, that was in 4th. When your SUV gets 18mpg in 5th and 16mpg in 4th, yeah, you just forget about MPG at that point.

ruking1

LOL. Actually, that is still (after 162,000 miles) one of the things that has not cease to amaze me about the combination. It is optimized for autobahn speeds. Although at times, I do still wish it came with a 6 speed manual. I can still put slighty bigger to wildly so injectors, etc., etc, and still have similar fuel mileage (if I don't get into it). If one is inclined to "get into it", one really should be upgrading the clutch combination. (to handle more torque and with a safety factor).

bumpy

No need to go that far back.



Easiest way to test the theory today would be a G25 versus a 4-cylinder Altima: both 2.5L Nissan engines, though the RWD versus FWD might moot the comparison.

fintail

Sadly, that never made it to this continent, although Canadians could buy it as they live in a less psychotic realm of importation laws.

Speaking of tiny I6, my fintail is just 2195cc, but at most speeds is extremely smooth. Gotta love the I6.

elias

hi Dudley.
To counter your point that no car uses a gallon per hour:
With the A/C on and with adulterated/oxygenated gasoline, my 2005 Pontiac ~20mpg car uses nearly a gallon per hour of gas.
Without A/C, it's about 0.6 or 0.75 gallons.
There are cars that get much worse mpg than my pontiac's ~20 mpg all-arond, ~24 mpg highway.
I'll bet some use about a gallon per hour at idle!
IIRC, another comparative datapoint is: my VW TDI uses about 0.25 gallons of diesel per hour at idle.
cheers,
/e

whobodym

my understanding from college level internal combustion engineering class, car magazine, etc. is that for a fixed value of displacement and horsepower, the maximum fuel economy will come from the fewest number of cylinders. People like lots of cylinders because they run smoothly, it's not for economy. Recall the mid-1990s Mazda MX-3 1.8L V6 -- sounded great, MPG and power was mediocre.

whobodym

the idea being, small numbers of larger cylinders have minimum friction; the opposite has more.

shipo

Of course not everything theoretical is proven out in the real world. While it is true that (in general), the fewer the cylinders for any given displacement the higher the fuel economy; unless the engine has at least six cylinders it works against itself due a phenomena called "torque reversal" (where the rotating mass of the crank and flywheel drive the engine instead of the other way around).

Think about it this way:
-- Given #1: each power stroke applies meaningful acceleration to the crank for only 140 degrees
-- Given #2: Only 2 power strokes occur every 360 degrees in a 4-cylinder/4-stroke engine
-- Given #3: There are two 40 degree periods per rotation of the crank in a 4-cylinder/4-stroke engine where the engine is doing everything in its power to stop rotating; only rotational mass of the flywheel is keeping things moving along on their scheduled rounds.

It is for this very reason that many 6-Cylinder engines of any given displacement easily outperform (in both rated power and fuel economy) 4-Cylinder engines of similar displacement. For your illustration you chose the poorly designed Mazda 1.8 liter V6; one end of the spectrum. The other end of course is the 2.5 liter I6 BMW was using in the E46 models; this was an engine which was every bit a match in all performance aspects to contemporary 2.5 liter I4 engines. In fact, I'd lay odds that if you were to run a 2004 325i against a 2011 Mazda3 GT, the 325i (in spite of its 200+ pound weight disadvantage) would literally run circles around the Mazda3 and get better fuel economy while it was doing it.

plekto

This is another reason why I suggested an I-6 engine. It is more reliable, smaller, and has less internal parts than a V6 engine. It also is the smoothest design other than a V12 and an I-12(which nobody makes short of old piston aircraft engines from WWII).

You get maximum economy, torque, and HP out of a 4-stroke engine from an I-6 engine. But it has to be very small to do so. As in 2.0L, optimally. Unfortunately, nobody makes engines like that. Mercedes did in the 50s and 60s - little 2.2L and 2.3L I-6 engines that were amazing at the time. Decently powerful, quick, and less weight that the other manufacturers.

ateixeira

Mazda MX-3 1.8L V6 -- sounded great, MPG and power was mediocre.

It only made 130hp, but remember, the I-4 1.8l only made 125hp. Ford used that inline motor tuned to 127hp (I owned a '91 Escort GT).

So the V6 actually had a tiny HP advantage. Perhaps not worth the complications and cost, though.

ruking1

While the current Edmunds.com information might not be complete, it seems the "ubiquitious" 2012 Camry will come with a 6 speed manual transmission .

nippononly

Now try and find one in stock anywhere in the country....I will give you a $1,000,000 if you find one. ;-)

stever

When's the deadline? :-)

About the 2012 Camry that's still in Pre-Production:

mcdawgg

Depends on what region you are in. I had to go to a different region to get my 2010 6 speed manual. In that region, most dealers had one. Give me $1,000 and I'll find you one.

dudleyr

I tried to buy a Camry stick in 2007 ( I love my Accord, but the nearest dealer is 200 miles away) and while there were some available as an SE, they all had sunroofs and I did not come close to fitting. There were absolutely no LE or standard Camry's with a stick.

Wound up with the Accord.

ateixeira

You could special order, but it would take 5-8 weeks.

mcdawgg

In the Central Atlantic region, almost all dealers had a base Camry and/or an SE with a manual - no problem at all finding one. An LE with a manual - I've never seen one.

benjaminh

He's 15. Smart and studious. A bit of a computer Geek. And yet wears his hair long. Maybe he's showing off cause his dad at 46 is getting thinner up top.

Anyway, I gave him his very first lesson in driving yesterday in an empty high school parking lot. It was in our 2010 Mazda5 Sport MT. We just started on 1st gear. He was able to get it going on the second try. Did stall out twice, but got it going three times and drove slowly around the parking lot at 10-15 mph.

Today we might try second. Or is that too soon?

I would like any and all suggestions of those who have successfully taught one of their kids to drive a manual.

At some point I think I need to find a close to empty rural side rode. Shouldn't be that hard, since I live in Louisville KY. May have to drive out of town at some point....

Thanks in advance, Ben

PS Our other car is a 2008 Accord EXL Navi 5MT. That car was c. 26k, whereas the Mazda was c. 16k. So, I have to admit I'm teaching him on the lower cost car.

shipo

I started our (then) fifteen year old son (Benjamin) out on my 2009 Mazda3 i Touring 5-Speed two and a half years ago; by the time he finished Driver's Training he was quite accomplished with stirring manual transmission gears. At one point his instructor commented to me that he felt Ben's ability to drive a manual transmission had turned him into the best young driver he'd taught in many years.

Our daughter turns fifteen later this year, and I'm thinking as soon as the snow melts next spring, she'll be getting her first lessons in the Mazda.

FWIW, trying second gear today is not at all too soon. :shades:

ruking1

Up shot: stay in the parking lot till she/he can execute flawlessly the ZERO to 5 mph actions. To me, a "protected" environment, like a parking lot is ideal to do almost all clutch work learning. The issue to me was never speeds of 5 mph on up, but being at relative to TOTAL comfort blending the actions (ZERO to 5 mph). Some other examples include: use of handbrake, parking to start on down hill slope, parking to start on uphill slope, not burning the clutch, what to do when you kill the engine with improper clutch action-when that big rig is 18 in behind you, etc.