With a MT (and assuming you don’t live somewhere flat like FL or western TX) you have a redundant starter system–one less SPF! (BTW, in the engineering world, SPFs are BAD things.) Happened to me: my GF at the time flew in to Farmington NM to see me, and we took my MT coupe out to see Mesa Verde NP–which happens to be in the middle of nowhere. Naturally, my starter dies at 6PM on a Saturday. I merely pointed the car downhill and we were on our way! (With an AT–hmm–spotty cell service, nearest town Cortez CO…where they roll up the sidewalks promptly at 5PM, gee, I guess we better hope there’s a vacancy through Monday!)
Ever since then, I will NOT purchase a new car with an AT–automatic deal-breaker! (pun intended). When you buy a jalopy, you take what they got, but if I’m spending more than $5k or so, no slushbox for me!
I seriously doubt that a late model car–like those in this discussion about fuel economy–can be push started. Without the signal from the car to wake up the electronics and a good clean signal from the crank sensor I think the car would still be a no-go.
Sorry skill has nothing to do with it…it’s computer controlled automatics with multiple sensors that give automatics the edge. Manuals are fun to drive…less money to maintain…cheaper to repair…but is most cases get worse gas mileage. Also automatics are MUCH better to tow with. easier and can tow more.
I seriously doubt that a late model car--like those in this discussion about fuel economy--can be push started. Without the signal from the car to wake up the electronics and a good clean signal from the crank sensor I think the car would still be a no-go.
I push started my Yaris once at a service station, after filling gas, the battery wouldn’t crank the engine. I put it in first, let it start rolling down the gentle incline, let out the clutch and had a running engine.
Yes, if the battery is completely dead, you won’t push start it but usually a battery too dead to crank the engine still has enough juice to pressure up the fuel system and fire the plugs and injectors.
Back in the days of mechanical fuel pumps, carburetors, and dc generators, you actually could push start a car with a completely dead battery.
I seriously doubt that a late model car--like those in this discussion about fuel economy--can be push started.
One quick way to find out for sure: go check out a hypermiling-oriented forum. MTs are highly sought-after there, because the bump-start lends itself to "pulse and glide" operations that save fuel. IF you can't bump start newer cars (and thus can't P-N-G them), there'd be a bunch of angry posts bemoaning that fact. I've never had any problem bump-starting any vehicle I've owned (granted, not "late model" per se, but it definitely works on OBDII stuff).
I’ll take your word for it, though I don’t see the need for the PNG. Most cars already shut off the injectors on decel or coast.
I do know I have worked on late model cars that would not start without input to the starting system through the key–even hot wiring at the starter would result in a crank but no start.
I'll take your word for it, though I don't see the need for the PNG. Most cars already shut off the injectors on decel or coast.
Even with fuel cut-off, there's the parasitic load of running an air pump: pumping air from low pressure (at the closed throttle plate) to higher pressure (at exhaust outlet). It's how you dump energy, descending a hill--downshift for high RPM at a closed throttle. The SAE has mileage competitions, and the winning design (heck, everyone) always operates under PnG. You can argue safety and if it's worth the PITA...but as an academic exercise, PnG will definitely burn less fuel over a road course than leaving the engine connected to the wheels the whole time will.
@MikeInNH, if automatics are more fuel efficient and better at towing, then why are long hual trucks these days are towing with automated manual? This is something that I’ve asked a couple of pages back. Automatics require a hydraulic pump to keep the wet clutches engaged to stay in gear, this power loss is not present in a manual, diy or automated. The fluid that’s trapped between the multi plate wet clutches is another source of drag when disengaged. This is why ZF uses two dog clutches, similar to a manual, in their 9 speed auto.
Long haul trucks have 18 speeds with low gears for launching with heavy loads. Just because auto manufacturers do not equip their trucks with low gears, it doesn’t make manual transmissions less suitable for towing. Truck manufacturers can’t afford to have trucks sitting in the garage not towing anything so they must pick the more robust equipment. When the trend moves toward automatic transmissions, automated manuals instead of slush box rules the road…
You can tell how efficient a transmission is by how hot it gets in use, and what means (if any) are used to cool it off. (Energy in-waste heat=energy out.) By that metric, a MT is more efficient than even the best AT is. Design compromises in a transmission CAN result in a total package that is less efficient in total, even though the transmission itself is more efficient at task. The main issue is that MTs seem to be built for “hoonability” and don’t employ miserly final drives. A better ratio would likely resotre the MT to the mileage forefront.
MikeInNH is right. If you look at AT technology the new AT’s have better technology and programming. My Mazda6 automatic lets me shift “manually” if I want with paddle shifters on the steering wheel or with the console shifter. Try as I might, I cannot do a better job shifting my car and getting better mileage than the smart AT, and I drove nothing but manual transmissions for over 20 years. I will not argue that a MT is simpler, easier to fix and allows push starts. On the other side of the argument, in my family (with many AT’s) we have had one transmission repair (a speed sensor wire corroded and frayed and the wire, not the sensor, was repaired). We have not needed to push start any cars, although we had to jump start a couple of the vehicles but, in each case, they were not somewhere that they could easily have been push-started, even if they had a MT.
Progress marches on and times change. We can be sentimental and stubborn about things changing, much like a generation of people once argued that horseless-carriages were not as good as horses for transportation. Or we can embrace the best of what is new if it is truly an improvement to our technology and lives. I love driving a stick shift. That doesn’t make it better. It just makes it more fun for me.
Talking about moving heavy loads,check out the current crop of dozers and loaders andsee how many are manual(there used to be a lot of squawking when torque convertor tractors were introduced,but the naysayers soon quieted down)most auto truck drivers I have spoken to,will tell you quite frankly,I didnt like the auto for 2 weeks,now I wouldnt go back.On rt 29 in Charlottesville,there are 30 plus stoplights between(stop cams too) Pantops and Ruckersville,after a day of rowing a manual in a underpowered overloaded truck,I would have welcomed a automatic transmission,theres a difference between open road and stop and go.So if like a manual fine,you are welcome to mine.Stirling Moss left this old boy a long time ago.
2:32AM
@MikeInNH, if automatics are more fuel efficient and better at towing, then why are long hual trucks these days are towing with automated manual?
Probably because of the difficulty to build a 18-gear automatic.
The weakest link in towing is the clutch. With light duty vehicles (SUv’s and cars)…the clutch is going to limit your towing capacity. Although they are tough to find now…but when many SUV’s came as either MT or AT…the AT’s had a higher towing capacity. My 90 and 98 pathfinders (both 5-speeds manuals) had a towing capacity of 3500lbs (Class-II). But the automatics were rated as 5000lbs (Class-III). Everything else in the drive line was exactly the same.
The reasons ATs can give better mpgs than MTs are the wide range of gears with the 6-9 speeds now common, and the integrated computer control of the engine and transmission, picking the best gear for each situation to maximize economy. Few people can do as well with a MT.
Even with the same number of gears, human beings couldn’t maintain the optimal operating gear as well as a modern automatic can. With a computer it’s purely responding to hard data. With a human, perception complicates the decisions. Computers don’t perceive, they just run sensor readings through algorhythms.
Honestly, I think it’s moot. In the near future I don’t thing true manuals will be generally available anymore except perhaps in specialty cars. I see everything changing to paddle-shifted automatics, not to be confused with the paddle shifted manuals used by exoticars.
Here’s an example of an 18 speeds automatic. They even offer a three years warranty on the clutch! My problem isn’t with the computer picking the correct ratio most of the time, just the machinery that the computer is controlling–the hydraulically activated transmission, which are relatively inefficient less reliable compared to manual transmission machinery
It’s true that an automatic’s hydraulics take a tiny amount of the engine’s energy to operate, but that’s more than made up for in its ability to maintain the optimal gear ratios without bias and without any preconceived notions or irrational preferences interfering with the pure physics of the decision.
But why settle for less efficient machinery when a more efficient machinery exist? Why can’t we have computer controlling more efficient, more reliable machineries just like modern trucks?
IMHO when the subject is shifting for efficiency, any system that gets shifted by a computer will overall be more efficient than one shifted by a human… even me. One cannot compare a computer shifted system with a truly manual system fairly without considering the human as part of the equation.
Don’t get me wrong, I greatly prefer manuals, and had it not been for medical considerations I would have gotten one on my current car (they were available). But I also recognize that I cannot shift the car as efficiently as a modern automatic can.
Unless driven by some boy racer who dogmatically believes the engine must always be in it’s “power band” even when going a steady 25 mph in a school zone, a human won’t be that far off on optimum shift points. The efficiency of an ICE does not fall off a cliff if the rpms are not perfect. Give us some credit for being able to judge shift points.
When a manual can’t match the highway gas mileage of an auto, it’s most likely because the manual’s highest gear is somewhat short compared to the automatic’s highest gear, not because the human can’t perfectly judge shift points.
So you have this computerized automatic that perfectly shifts the transmission as you accelerate towards each and every red light, and you wonder why I still kick your butt when it comes to fuel economy with my imperfect manual transmission.
In two of the same year/make/model/equipment (except for the trannys) cars, both driven comparably, I seriously doubt that you’d kick anyone’s butt with the manual. But this is a purely hypothetical situation, and. we’ve simply drawn different conclusions.
