AMG badge......

[wivenhoe]

We like it because the non-British find it difficult to use.

The Americans continue to use it. I remember the days when the building industry was still using it - to work out say how many sq ft in a room was a nightmare, even more so before calculators - say 16’ 5” x 19’ 8” compared with 5m x 6m
Apologies to the OP for going off post

 

[Deleted member 126251]

So the old system is very ingrained in our society and our language. In engineering however, the U.K. adopted metric decades ago pretty much across the whole piece. Unlike the USA where it is still a horrid mixture of both, metric, imperial and "mercan" (density in slugs, temperature in Fahrenheit etc.). Metric is so much easier to work with mathematically.

Question was very much tongue in cheek. I have been using metric for over fifty years but still say I'm 6'2" tall and weigh 102kg! Although these days, the first number seems to be getting smaller and the second getting bigger.......

I worked on a project in the 90s that started in New Orleans (engineering) and ended up in Iran Jaya(installation) ) designed in the USA but for a metric country (IFC & "as built" drawings had to be metric) - we had a lot of problems when steel started arriving on site and people realised that calculations had gone wrong all over, because of converting sizes to metric. I'm happy to say that I was not responsible for that.

 

[E53AMG]

Oddly when it's cold it's 1 or 5c but when on holiday it was 90f. I guess it is back to nm v lbft discussion.

Sent from my SM-G955F using Tapatalk

 

[Bellow]

We could of course use that other 'metric' of length - the football pitch.

 

[tbourner]

Volume is normally measured in "Olympic swimming pools", not sure if that's metric or not. I guess it must be as Americans tend to use football stadiums for that as well.

 

[GeeJayW]

Olympic swimming pools are usually defined in metric units for length, i.e. 50m long. My guess is that their width and depth are also specified/defined in metres. The contents therefore being in thousands of litres or cubic metres, though of course may well be expressed in gallons which requires some sort of conversion from one system of measurement to another.

However, the use of 'Olympic swimming pool' or 'football pitch' or 'double-decker bus' etc. as metrics for describing the volume or area of something else, doesn't require them to be defined in metric units per ce. In the same way that something defined as being small enough to fit on the head of a pin. We instinctively know that a swimming pool or football pitch is large and that the head of a pin is small (but not microscopically small). So these terms are useful for establishing a perception of scale rather than an exact measurement of size. I don't even know what the typical size of the head of a pin is, but it's usually pretty small though not as small as the point.

We in the UK, adopted the SI (metric) system of measurement decades ago. I was at school and college at the time, had to learn both and had to take exams that could be in either. In just over forty years of engineering, most of the projects I was involved with required me to work in metric units. A big difference was when working with the US, when I ended up having to work in metric, imperial and whatever it is the US use which seems to be a strange mixture of everything.

Socially, I've always gone down the pub for a pint, think of my weight in stones (even though I know it better in kg), my height in feet and inches (I only roughly know what that is in metres), my waist and chest sizes are inches, I have no idea without thinking about it, what they are in centimetres and I take size 9 shoes which I think is 43 in European sizes and I have no clue how that relates to the metric measurement system. Overall, it's a bit of mess but somehow it sort of works most of the time.

And if someone wants to put an AMG badge on their non-AMG car and whether that is in inches, millimetres, chains, furlongs or light-years is all fine with me.

 

[Alex225]

I'm gonna be boring here and reply to the OP just about badges! hahaha

People can do what they like with their cars, ultimately they could stick a Porsche badge on a Volvo for all I care. I do think though, that fitting a non-factory AMG badge to a non-AMG Merc is just a but sh!t.

To me, AMG represents the powerful engines that AMG build and in turn those cars are styled accordingly. Some Mercs have AMG styling on them and have the badges but they are factory lookalikes basically. I personally wouldn't want an AMG badge on a diesel for example even if it had the styling. I have re-mapped and slightly modified my E320, it's now de-badged and I wouldn't dream of putting an AMG badge on it.

I'm part of a couple of Merc Facebook groups and one guy bought a personalised number plate with AMG on for his E220 and another fitted AMG badges on a diesel.

There's nothing wrong with a non-AMG Mercedes!! They're still stylish, nicely made, decent cars so I don't see who anyone needs to kid.

 

[Deleted member 6183]

This thread.

 

[Bellow]

Torque to be measured in N.fp (Newton.football pitches)?

Another - and with a specific question I'm hoping GeeJayW can answer.
g/kWh. Yes, BSFC can be expressed several ways but sticking with g/kWh, what is a typical (full load) figure for an efficient modern day petrol engine? A quick perusal of the 'net suggests around 300, possibly as low as 280g/kWh over a narrow speed load band. Does that sound about right? What would be the figure for diesel - about the same?

 

[TwoDogs80]

I'm gonna be boring here and reply to the OP just about badges! hahaha

People can do what they like with their cars, ultimately they could stick a Porsche badge on a Volvo for all I care. I do think though, that fitting a non-factory AMG badge to a non-AMG Merc is just a but sh!t.

To me, AMG represents the powerful engines that AMG build and in turn those cars are styled accordingly. Some Mercs have AMG styling on them and have the badges but they are factory lookalikes basically. I personally wouldn't want an AMG badge on a diesel for example even if it had the styling. I have re-mapped and slightly modified my E320, it's now de-badged and I wouldn't dream of putting an AMG badge on it.

I'm part of a couple of Merc Facebook groups and one guy bought a personalised number plate with AMG on for his E220 and another fitted AMG badges on a diesel.

There's nothing wrong with a non-AMG Mercedes!! They're still stylish, nicely made, decent cars so I don't see who anyone needs to kid.

Amen!

 

[400ixl]

To me, AMG represents the powerful engines that AMG build and in turn those cars are styled accordingly. Some Mercs have AMG styling on them and have the badges but they are factory lookalikes basically. I personally wouldn't want an AMG badge on a diesel for example even if it had the styling. I have re-mapped and slightly modified my E320, it's now de-badged and I wouldn't dream of putting an AMG badge on it.

But not necessarily to many of the younger generation who have grown up to see AMG as both a styling arm which can also have a performance element. The AMG thoroughbred view is just going to be more and more watered down in a similar way the M-Sport has done to the M series for BMW and the S-Line has done to the RS series for Audi. As the market for the thoroughbred shrinks, the more that they will use the branding to sell to the masses. It won't be long before the AMG badge does appear on the boot (and not just wheels / floormats etc) from the factory on styling models.

Personally my AMG styled car is debadged and I wouldn't put an AMG badge on it, but if others feel they want to then that is up to them. Most others won't care (and don't know there is a difference between AMG styled and AMG engined) and those that do care will probably get wound up over it (for 5 seconds), some even confrontational (hopefully a very small minority). Watched someone have a right go at someone recently trying to mock them over the badges they had put on their car. Got most upset when he got told to get a life and stop being a bully.

 

[GeeJayW]

Torque to be measured in N.fp (Newton.football pitches)?

Another - and with a specific question I'm hoping GeeJayW can answer.
g/kWh. Yes, BSFC can be expressed several ways but sticking with g/kWh, what is a typical (full load) figure for an efficient modern day petrol engine? A quick perusal of the 'net suggests around 300, possibly as low as 280g/kWh over a narrow speed load band. Does that sound about right? What would be the figure for diesel - about the same?

That's a bit like 'How long is a piece of string?"...
So much depends on a number of different factors.
Back in the day when gasoline engines were about 25% efficient, BSFC comes out at about 330 g/kWh if one assumes a fuel energy density of 43MJ/kg. High-speed Diesel engines were a bit more efficient at around 30% so come out at about 280 g/kWh.

Today, engines are more efficient, especially down-sized boosted designs with some gasoline engines pushing 40% which was unimaginable when I was studying. So this comes in at about 200g/kWh.

I saw something a while back that said current hybrid F1 engines are now better than 50% for thermal efficiency. So that comes in at 160g/kWh which is astonishing.

Hope that helps.

 

[400ixl]

5% of that efficiency comes from the MGU-K alone. Part of why manufacturers want to keep the Hybrid formula.

 

[GeeJayW]

5% of that efficiency comes from the MGU-K alone. Part of why manufacturers want to keep the Hybrid formula.

Ah, but how much extra efficiency comes from the AMG badge on the side of the car?

 

[Bellow]

Cheers GJW.
Picking up on this....

Today, engines are more efficient, especially down-sized boosted designs with some gasoline engines pushing 40% which was unimaginable when I was studying. So this comes in at about 200g/kWh.

.....would it be fair to say that 40%TE is only obtainable at peak torque and elsewhere in the load speed range it is (possibly significantly) lower?
I read some time ago that the OEMs didn't make the fuel savings expected of the downsized (boosted) SI engines and one of the reasons cited was part-load inefficiency due to exhaust backpressure created by the turbo in the exhaust stream when not boosting. The inevitably lower CR was also mentioned IIRC. Also, 40% is quite a jump from previous TEs. Would those be GDI engines? But GDI's advantage lies more at part-load and presumably BSFC is quoted at peak torque - where GDI offers little benefit. 200g/kWh is way lower that I've ever heard of.

I saw something a while back that said current hybrid F1 engines are now better than 50% for thermal efficiency. So that comes in at 160g/kWh which is astonishing.

I've seen that 50% TE for current F1 engines quoted too (though as mentioned elsewhere, partly due to its hybrid element). That puts them on a par with the most efficient piston engines to date that can be found in the largest ships, operating on the 2T cycle at circa 80 to 100 rpm.

 

[GeeJayW]

Highest TE is typically around the point of peak torque as that is an indicator of the best charge efficiency for a given set of engine conditions, but it depends on a lot of factors especially if the engine is boosted. Some important improvements come from reducing the frictional losses in the engine through improved lubricants, the use of friction modifiers in fuels, ceramic and other coatings (e.g. DLC) on some components, improved engine/turbo design and so on. I wouldn't expect to see 40%TE across a wide operating range.

As you say, the big marine diesels were always held as an example of best TE.

I was a bit surprised when I read that F1 engines were up there, especially given that in the past they were pretty awful from a TE viewpoint. The contribution of the hybrid system as mentioned by @400ixl is important too.

 

[SW18]

I had to take to the interweb to understand some of the acronyms in the last few posts! But now I get it, and it’s interesting. It leads to a question I have been wondering about, which is: how do electric cars compare in terms of energy consumed per kWh produced? Is it better due to lack of losses to mechanical parts?

 

[Bellow]

Highest TE is typically around the point of peak torque as that is an indicator of the best charge efficiency for a given set of engine conditions, but it depends on a lot of factors especially if the engine is boosted. Some important improvements come from reducing the frictional losses in the engine through improved lubricants, the use of friction modifiers in fuels, ceramic and other coatings (e.g. DLC) on some components, improved engine/turbo design and so on. I wouldn't expect to see 40%TE across a wide operating range.

A peak torque figure then, and lower elsewhere. Which would coincide with the very variable fuel returns from such engines depending on how they are driven. It's a curse though, that full load running still requires mixture enrichment.

As you say, the big marine diesels were always held as an example of best TE.

Cathedral diesels - well named!

I was a bit surprised when I read that F1 engines were up there, especially given that in the past they were pretty awful from a TE viewpoint. The contribution of the hybrid system as mentioned by @400ixl is important too.

I guess, with everything they learned in cutting friction in the previous screamers, the hybrid contribution (they really must be extracting from the exhaust energy as much is is physically possible), state of the art cooling (allied to reasonably fast rpm) and low pumping losses (air and fluids) then TEs where they are quoted are valid. With maybe just a percent or two added to make the case for keeping the engine regs as they are.....

Apologies for the thread jack - but this is the stuff the badges are supposed to be about! (And it's not like it's never been covered before...)

 

[Bellow]

I had to take to the interweb to understand some of the acronyms in the last few posts! But now I get it, and it’s interesting. It leads to a question I have been wondering about, which is: how do electric cars compare in terms of energy consumed per kWh produced? Is it better due to lack of losses to mechanical parts?

To compare EV and ICE is difficult as electrical generation becomes relevant for the EV to the overall picture - as does inefficiencies in oil extraction and refinement for ICEs. The 'well to wheel' figure is the overall determinant of ecological efficiency.

For the vehicle itself - for say, 33% TE with an ICE car, roughly, 1/3 of the fuel energy is made available to drive the car, another 1/3 is lost as exhaust heat (though some can be recovered in a turbocharger to help reduce the energy expended in filling the cylinders with air) and the final 1/3 is lost to friction which comprises largely oil friction and its pumping and ends up as heat discarded to the cooling system along with some combustion heat lost there also. On top of that, in the absence of turbocharging, energy is expended in drawing air into the engine (pumping loss).

Contrast that with no exhaust loss and no combustion heat loss, no air or fluid pumping for the EV and its efficiency should be much higher. How much higher I do not know. There are still losses due to heat from the electrical currents (all very carefully managed) and some energy required to drive the associated cooling system. The motors themselves are as good as friction free (unlike ICEs) and that leaves the chemical efficiency of the battery (charging and discharging) to complete the losses.

Comparing the two (ICE and EV), the onboard losses for the EV should be substantially lower hence its onboard efficiency much higher.

 

[GeeJayW]

I had to take to the interweb to understand some of the acronyms in the last few posts! But now I get it, and it’s interesting. It leads to a question I have been wondering about, which is: how do electric cars compare in terms of energy consumed per kWh produced? Is it better due to lack of losses to mechanical parts?

BSFC is well understood for ICe applications and ignores the energy used in producing the vehicle and the fuel.

On the other hand the efficiency of EVs is really tricky to evaluate as it depends a lot on where you put the boundary conditions. Ignoring the energy needed to produce the vehicle is probably fair. Measuring the kWh drawn from the grid during charging is easy, but how much of that is retained by the battery is pretty much up for grabs. Then measuring how much is produced by the motor during discharge is again fairly easy to do, but at the end of the test who knows what energy is still in the battery?

I was involved in some test work on EVs a few years ago, but to be honest it was right near the end of my career and EVs were not common at all. The first examples we had to play with were converted by a small company and were effectively prototypes. The motor and battery technologies were quite primitive and overall they were not especially impressive or representative of what is out there now. The Nissan Leaf had just become available and we had started to work with those, but then the programme (and I) moved on.