Economics of hypermiling vs. vehicle longevity

[redyaris]

What some one with an upper grill blocker and a scanguage could do is select engine/coolent temp on one of the displayed guages and do an EOC and see what the guage reports. I suspect that there would be little if any change in engine temp. all engines heat socke when the car is stoped/parked and turned off which would be no different than turning off the engine when coasting. Although when coasting there is some cooling due to forward motion through the air...

[cbaber]

Originally Posted by redyaris

What some one with an upper grill blocker and a scanguage could do is select engine/coolent temp on one of the displayed guages and do an EOC and see what the guage reports. I suspect that there would be little if any change in engine temp. all engines heat socke when the car is stoped/parked and turned off which would be no different that turning off the engine when coasting. Although when coasting there is some cooling due to forward motion through the air...

I don't have a grille block but I did watch my coolant temperatures while doing P&G on one of my commutes. Before my ScanGauge I thought the engine was actually running cooler than normal because of the EOC. The factory gauge reported the temperature to be below where it normally sits while the engine runs constantly.

Come to find out the engine temps stayed right at the normal level while doing P&G. My civic stays at 193-198 degress F and that was were it was the entire commute, even though the factory gauge showed it was lower. I believe this is because the factory gauge shuts off when I EOC and it never had the chance to fully move up to the correct spot before I turned off the engine each time.

The best indicator of engine bay temps is the intake air temperature gauge on a ScanGauge. I don't have a grille block and mine has seen up to 130 degrees F in hot weather. If you block the grille you need to watch engine temp and IAT in order to see if the heat becomes excessive. You don't want the radiator fan to be running more than normal, and you don't want the engine bay to be close to the engine temps.

It should be noted that the materials inside the engine bay were designed for heat. The rubber hoses can withstand engine temps all day, some of mine run inches from the block itself. The belts are not only close to the engine, but they rotate at thousands of RPM's and I believe could generate a lot of heat just due to the friction alone. I don't believe for a second that running a grille block will shorten the life of any engine bay components.

[MPGranger]

Originally Posted by euromodder

Pretty remote from car tech, isn't it ?

Seeing the loggers on Discovery ... even taking into account it's for telly ... hardly representative for car use.
Run it hard until it breaks, then moan about it, seems to be the norm.

His milling equipment may well date a good while back, or be designed in old fashioned "unbreakable" style.
That equipment was easier to fix, and to keep running by adding ever more oil, thicker oil as they wore down, then new rings, resleeving ...

My Brother-n-law is school trained and certified. The mill does not run off of a water wheel anymore. Do you have any idea how much wood gets milled each day? Go to your local hardware store, there's a lot of downed trees in there. They have laser guided saws, trying to maximize boards per tree. What you see on TV is a highly edited version of the truth. But those are the lumber jacks, not the mill wrights. Mill wrights keep the mill running, that's where the money is made.

But I need to get him to read this thread. He brought up some intriguing points and I didn't know how to respond being in a subject he is intimately familiar with. Plus he should be able to fire back and add some fuel to the fire. I think it is good to be able to debate this type of thing.

EDIT: I think I need to remove the grille block off the Ranger and DWL with it and see where the engine winds up.

[SentraSE-R]

I was experiencing high coolant temperatures in Winter 2011-2012 with a full grill block. If I P&Ged (engine on), coolant temperatures stayed about 186ºF during highway trips. When I had to run the engine steadily, temperatures climbed to 204ºF. I later found I had a pinhole leak in a radiator hose, but the point was made. My engine ran cooler with engine on P&G than it did cruising at roughly the same steady speed.

[Occasionally6]

Originally Posted by euromodder

Which may not go down well with the catalyst ...

(Referring specifically to bump starting): Why is that different to turning the engine over on the starter?

Originally Posted by RedDevil

My car does a kind of EOC coasting all by itself. The engine does not really shut off, but the valves will open completely and no gas is injected so the pistons move freely in clean air.

Are the valves open or are they closed? From the point of view of reducing pumping loss and air cooling the catalytic convertor, I'd say they're closed if they are being disabled.

Something else: The premise behind pulse and glide is to operate the engine at high load. I expect that is also going to wear out the engine faster than operating at 'normal' loads. Against that the duty cycle is lower.

[RedDevil]

Originally Posted by Occasionally6

(about EV mode in the Insight: )
Are the valves open or are they closed? From the point of view of reducing pumping loss and air cooling the catalytic convertor, I'd say they're closed if they are being disabled.

The intake valves are wide open during that mode. Letting the air move freely in and out the engine at low revs does not put any stress on the piston, closing all valves all the time would either create a big vacuum on the downstroke or high compression on the upstroke, which cause much more friction.
Dunno about the output valves. It seems logical if they are kept closed, but haven't actually seen it.
This mode is operated by an extra camshaft (Honda VTec). The engine actually has 3 camshafts; EV mode, efficiency mode, power mode. A bit much for a simple 8 valve 4-potter

Originally Posted by Occasionally6

Something else: The premise behind pulse and glide is to operate the engine at high load. I expect that is also going to wear out the engine faster than operating at 'normal' loads. Against that the duty cycle is lower.

Load need not be realliy high, just efficient.
If your engine does 3000 RPM@60mph in top gear, it will probably lose more power on pumping losses than it produces. It could produce say 3 times as much power for just twice the fuel consumption by mildly accelerating at say 40% of WOT. You'd save 33% by P&G-ing then, but stress on the engine would still be way lower than what it is designed for.

My engine does just 1900 RPM or so at 60 mph so the throttle has to open further, and pumping losses are reduced. It is hard,maybe even impossible for me to gain anything by P&G-ing at highway speeds.

[Frank Lee]

"So my brother-n-law recently visited and was asking some interesting questions about some of the techniques I use. He works at a lumber mill in Oregon, specifically he is a mill wright. So he professionally does maintenance on heavy duty machinery. He is not an apprentice, he is a fully certified mill wright. A lot of his questions center around diesels, but overlap to gasoline.

1) Grille blocks, engine heating in the summer, engine insulation. He claims that higher temperatures for longer times is reducing the lifetime of the engine. He says that the higher temperatures actually change the molecular composition and weakens the metal."

Pshaw. The temps aren't that much higher. Insulation as it is on my stuff mainly serves to prolong cool-downs thus reduce cold starts while not increasing running temps- according to coolant gauge- all good stuff.

"2) Running thinner lubrication. He says that thinner lubes essentially run like water, increasing friction. So this adds excessive heat, which due to thermal expansion increases friction again. All in all, greatly increases wear."

I wouldn't go thinner than the OEM recommends for winter ops, but I run that year-around.

"3) EOC. Wears out batteries, wears out starters, wears out cooling system, wears out engine."

I usually bump start plus I have less urban/commuter ops than the average bear (more highway) so it's possible I am easier on the battery and starter than the average motorist! Re: wears out cooling system and engine: I fail to see how.

[IamIan]

Originally Posted by MPGranger

1) Grille blocks,
2) Running thinner lubrication.
3) EOC.

None of these seem to have significantly reduced the Longevity of the guy who past 500,000 Miles back on 4-5-2011 , on his 2000 Honda Insight ... which does some amount of all of these even in an OEM car even before any mods.

[justme1969]

Add a Led light into your cooling fan circuit.
This light can tell you if your fan runs constantly or intermittantly.
It is harder to decipher the results if there is only a single fan but, after a
week you can see the trend develop of on and off cycles.
If it runs constant it is possible you left the A/c on and have that as false reading, if wired into wrong fan.
or mabe a grill block is blocking air that the system needs to get below the switch temp.
If you have an issue with your cooling system prior to grill block it will Let you know so.
Ive grill blocked 6 cars in last few months with no issues other than my own.
It ran the cooling fan constantly after the air dam blocked all frontal air completly. I left the small opening open and now fan runs for 45 seconds every 11 minutes unless Idleing then its still 45 sec.but more frequent.

ya get all that clear as mud eh? sorry im tired!

[elhigh]

I've been using EOC, bump-starting and other hypermiling techniques for decades on the same vehicle and can tell you that it doesn't appear to have affected the longevity of my vehicle negatively at all.

Since my truck is approaching "outlier" territory on the graph of vehicle ages, you start to think that mine was either built on a Wednesday or that hypermiling is sufficiently gentler to a vehicle that, other factors being equal, it lasts longer than a non-hypermiled vehicle.

When I add a grille block (need a new radiator first), I'll try it out for fifteen years or so and get back to you whether it seems to have killed the truck.