Why don't manufacturers "Map" their engines

[nickfrog]

laingy said:

I guess the question should be why don't manufacturers map the cars to the country they are selling them to, and not have to worry about one map fits all?

Because new cars often get re-shipped to a different country than its country of destination. Very easy within the "LHD zone".

[DKS]

Also, just thinking here, a proper mapping session takes time with one particular car and engine on the rollers. A manufacturer doesn't want to 'map' each car it builds, so has a fairly safe map it can just roll out on thousands of cars and expect them to work. Every engine is different.

[AER]

laingy said:

I guess the question should be why don't manufacturers map the cars to the country they are selling them to, and not have to worry about one map fits all?

To some extent, sometimes they do, although they tend to be "markets" rather than specific countries. Usually they are calibrated to allow for a lower minimum fuel quality and it goes along with lower compression ratio engines and other subtle hardware changes.

As Max alludes to, most "mappers" are selling snake oil at worst or, at best, trading off some component lifespan for more "go", something that they either don't know themselves exactly, or are not willing to tell you.

With modern SI engines running modern controllers with knock sensing, there is very little performance variation engine-to-engine and no performance knobbling to speak of that is emissions-related. With diesels you can make better fuel economy and power, but not whilst still meeting emissions requirements - obviously manufacturers are unable to sell you something that doesn't comply.

[Pints]

greggy50 said:

Also in case of VW etc... they map the cars so the VW is not quicker than a more expensive model

Take the mk5 edition 30 GTI exactly same engine that is in the Audi S3 running 265bhp in the Edition 30 it was tunned to 230 most likely due to the fact that otherwise it would be quicker than the R32!

Also in the case of the 150bhp and 180bhp Golf Mk4 they can charge you a lot more for a standard remap by having the two "different" models

Then of course they is all the other valid reasons above

Don't forget the 140bhp and the 170bhp TDI of the mk5.

And it's not only VW who are at it.

BMW used the same 2.0l lump in everything from the 116d to the 123d.

[Mave]

WeirdNeville said:

And given that the EU test cycle is at the forefront of the manufacturers minds when they develop the initial map for the car. I doubt you could ever better it.

but why would you want better eu cycle fuel consumption when noone drives the eu cycle in the real world?

[Mr2Mike]

otolith said:

But then who would pay to get their car optimised for that cycle, given that they will never actually drive it like that?

According to their claims the map is already optimised to gain better economy, as well as power. If their claims are true then back to back testing under the exact same conditions would prove (or much more likely disprove) this, no further optimisation should be needed.

[nottyash]

creampuff said:

I don't believe the "increase power and fuel economy" claims from remaps either. You can't do both and if it was that easy then the manufacturers would do it. Well maybe remaps could do it a bit by going closer to a 14:1 air:fuel mixture but at the expense of higher engine temperatures.

I've yet to see any reports from people who sound like they know what they are talking about where it goes on a dyno AND they measure fuel consumption.

In my experience I have noticed gains in mpg and big power increases.
My Fabia Vrs TDI went up 2 mpg on the longer motorway journeys I used to use the car for.
However it went down 2 mpg around town. You can't get gains in all areas.

[Kawasicki]

Pints said:

greggy50 said:

Also in case of VW etc... they map the cars so the VW is not quicker than a more expensive model

Take the mk5 edition 30 GTI exactly same engine that is in the Audi S3 running 265bhp in the Edition 30 it was tunned to 230 most likely due to the fact that otherwise it would be quicker than the R32!

Also in the case of the 150bhp and 180bhp Golf Mk4 they can charge you a lot more for a standard remap by having the two "different" models

Then of course they is all the other valid reasons above

Don't forget the 140bhp and the 170bhp TDI of the mk5.

And it's not only VW who are at it.

BMW used the same 2.0l lump in everything from the 116d to the 123d.

You can never be 100% sure that the parts are identical between lower and high powered versions of the "same engine". For example the 116d might have a cast crank, while the 123d might have a forged crank. Car manufacturers aren't daft.

[The_Burg]

The classic 'hobbled' car has to be the MINI, 1.6 and Cooper identical engines but the throttle doesn't open full on the cooking 1.6. Seem to have a recollection of Clarkson advising people not to buy the Cooper as it could be fixed for a couple of hundred?

[kambites]

WeirdNeville said:

Well, precisely, but the original point was that aftermarket mappers could run their map through the EU test and see if they actually get better results.
My argument is that I don't think they would. They don't have the resources to compete with the manufacturers, whose primary goal (or one of them) is acing that very test.

I don't think anyone is claiming that they would give better results on the test and I'm absolutely sure they wouldn't. I think they claim that they would give better results when the car is driven on the road precisely because they don't focus on the test.

[Wills2]

Kawasicki said:

You can never be 100% sure that the parts are identical between lower and high powered versions of the "same engine". For example the 116d might have a cast crank, while the 123d might have a forged crank. Car manufacturers aren't daft.

Indeed not to mention another turbo, the PPP c63 has 30hp more than the standard car but Merc gives it stronger internals, BMW do offer power upgrades to some of their engines but then fit better cooling along side it.

[viggyp]

I've not read all the posts but my motor had a remap (It's adjustable) and what it did was reduce turbo lag which my car has in abundance and improve economy which is what i wanted. Rather than drop it into second whilst approaching a roundabout, I can keep it in third (It's only a 1.2 diesel) and it pulls nicely. The best fuel consumption the car recorded was an avereage of 74.1 mpg which included city driving but mostly A roads and motorways.

[98elise]

Its like asking why all cars don't come with 18 inch wheels, and fat tyres....as they improve handing.

Manufacturers are in the business of selling cars, and they will build a range of cars to meet the biggest market they can sell to. That means "mapping" the engines to what ever the majority of people want.

[kambites]

98elise said:

Its like asking why all cars don't come with 18 inch wheels, and fat tyres....as they improve handing.

Probably not the best of examples, since I've yet to drive a car which handles better on optional 18 inch wheels and wide tyres than the standard smaller setups.

[German]

otolith said:

Max_Torque said:

Funny thing, although load of tuners claim "better fuel economy" not one (as far as i am aware) has had one of their cars tested over the EU std test cycle. Something that costs as little as £1k. Now i wonder why that may be................

But then who would pay to get their car optimised for that cycle, given that they will never actually drive it like that?

I'd argue almost everyone already pays to have their car optimised for the cycle....when they buy it new

[Toltec]

Quite a few manufacturers now have sport buttons which change the map and other settings on a car.

[98elise]

kambites said:

98elise said:

Its like asking why all cars don't come with 18 inch wheels, and fat tyres....as they improve handing.

Probably not the best of examples, since I've yet to drive a car which handles better on optional 18 inch wheels and wide tyres than the standard smaller setups.

I should have put improve in quotes!

[Engineer1]

laingy said:

I guess the question should be why don't manufacturers map the cars to the country they are selling them to, and not have to worry about one map fits all?

Sorry I'm a bit stuck my Dutch spec BMW is running rough on this alpine pass, and really struggled on that crap petrol from the Romanian garage.

The other reason is if they go all out on the engine at day one there is no scope for improvements or developments down the line, look at the old VW 1.9TDI that engine was anything from 90 -130 bhp

[Otispunkmeyer]

Kawasicki said:

You can never be 100% sure that the parts are identical between lower and high powered versions of the "same engine". For example the 116d might have a cast crank, while the 123d might have a forged crank. Car manufacturers aren't daft.

Correct, I believe the 118d had lesser spec'd injectors to the 120d for instance.

[Benrad]

Don' know if anyone has said it but it's perfectly possible to increase power, torque and fuel economy with a map on a diesel.

NOx limits are currently the thing we spend most time aiming at (for lorry engines that I do anyway) and if you took those away we could have ~20% better economy for the same torque at a guess. That's why lorries can afford to run AdBlue to reduce NOx, it has a corresponding fuel economy benefit.

In order to get NOx down you have to reduce peak cylinder pressure and temperature which are exactly what you need for best efficiency, mean effective pressure etc.

So for diesel as long as you don't mind causing acid rain and global warming (NOx is worse than CO2) you can have your cake and eat it with a remap... just as long as the clutch/gearbox etc can take the torque!