Requested a refund on a second hand 2018 BMW

DrEskimo

1. Those are just estimates. Some EVs can be quite accurate once it gets used to your general driving habits, but I never knew of any petrol car that did a good job on estimated range. Wouldn't pay much attention to them and certainly not indicative of a major fault.

2. The range seems comparable to other users in the colder months. How much were you expecting?

You don't have an option to simply hand back for a refund. You need to give the dealer a reasonable chance to fix the issues, so would get it booked in and can sort out most of those minor issues. If the error message persists, then you can think about escalating it.

ontheroad1970

Ditzy_Mitzy said:

Re point three, are you really attempting to complain about the fact that your car's heater, when set to maximum, made the interior 'too hot'?  

It would certainly  be a valid complaint if it was operating outside f its designed parameters.

LunaLater

blippi88 said:

Range is always worse in winter, both for combustion engine and battery. Appears to be a case of buyers remorse.

That’s not correct. Many internal combustion engines will operate at higher efficiency in colder weather.

Carnot efficiency increases with reducing absolute temperature.

Ditzy_Mitzy

LunaLater said:

blippi88 said:

Range is always worse in winter, both for combustion engine and battery. Appears to be a case of buyers remorse.

That’s not correct. Many internal combustion engines will operate at higher efficiency in colder weather.

Carnot efficiency increases with reducing absolute temperature.

Nah.  The above comment is incorrect for several reasons.  In cold conditions, engines spend longer in the warmup phase, which requires more fuel to be burnt.  A cold engine requires a richer mixture, provided either by the choke or cold start programme if fuel injected, which in turn requires more fuel.  A cold engine also has cold oil, which is stickier and more resistant to turning, requiring more fuel.  A cold car does the same: the gearbox and all the bearings will be stiffer, again using more fuel.  Heaters, demisters, lights, windscreen washers and everything else you use in the winter require fuel.  

Moving on to Carnot efficiency and a warm engine, as alluded to by the previous poster: yes, in theory, an engine should be more efficient if it's cold.  In fact, many engines are m. ore efficient in cooler conditions - but this is usually reflected in generation of additional horsepower rather than less fuel usage.  Cold air is denser than hot air, meaning more of it - at the molecular level - will be taken into the cylinder on the induction stroke.  An electronic injection system knows that, being capable of measuring both volume and temperature of the inlet charge; it can then adjust the fuel delivery accordingly to maintain the appropriate stochiometric ratio (thank you science lesson).  All things considered, more fuel should be injected in order to compensate for the greater air volume.  Bigger burn.  More power.

The injection computer doesn't have to make that decision, of course, but some will, ergo fuel consumption and power increase as ambient temperatures drop.  A carburettor can't adjust itself, but could be retuned to take the colder temperatures into account.  

macman

Did this 4 to 5 year old car not come with some form of additional warranty? Dealer, based, insurance based, or even 'BMW Approved' or similar? i'd expect something of worth on a vehicle that could be little more than a year out of manufacturer warranty.
The slow puncture could well have occurred during your week of ownership, but they've offered to fix it anyway.

diystarter7

Hi

TBH, the dealers being kind to you re puncture repair as you can have a puncture a moment after driving off,

The battery and feul use is always lower in the colder weather

The Jeep I had years ago, a GC, in winter short trips of 2 miles it was register 12/13mpg 

If the dealer takes the car back, will you be buying the same make/model?

Thnaks

LunaLater

Ditzy_Mitzy said:

LunaLater said:

blippi88 said:

Range is always worse in winter, both for combustion engine and battery. Appears to be a case of buyers remorse.

That’s not correct. Many internal combustion engines will operate at higher efficiency in colder weather.

Carnot efficiency increases with reducing absolute temperature.

Nah.  The above comment is incorrect for several reasons.  In cold conditions, engines spend longer in the warmup phase, which requires more fuel to be burnt.  A cold engine requires a richer mixture, provided either by the choke or cold start programme if fuel injected, which in turn requires more fuel.  A cold engine also has cold oil, which is stickier and more resistant to turning, requiring more fuel.  A cold car does the same: the gearbox and all the bearings will be stiffer, again using more fuel.  Heaters, demisters, lights, windscreen washers and everything else you use in the winter require fuel.  

Moving on to Carnot efficiency and a warm engine, as alluded to by the previous poster: yes, in theory, an engine should be more efficient if it's cold.  In fact, many engines are m. ore efficient in cooler conditions - but this is usually reflected in generation of additional horsepower rather than less fuel usage.  Cold air is denser than hot air, meaning more of it - at the molecular level - will be taken into the cylinder on the induction stroke.  An electronic injection system knows that, being capable of measuring both volume and temperature of the inlet charge; it can then adjust the fuel delivery accordingly to maintain the appropriate stochiometric ratio (thank you science lesson).  All things considered, more fuel should be injected in order to compensate for the greater air volume.  Bigger burn.  More power.

The injection computer doesn't have to make that decision, of course, but some will, ergo fuel consumption and power increase as ambient temperatures drop.  A carburettor can't adjust itself, but could be retuned to take the colder temperatures into account.  

For you science is mainly something which happens to other people, isn’t it?

Why would anyone try to bring in a carburettor, something which hasn’t been a normal part of cars for many decades now?

You’ve even admitted in your post that many engines are more efficient in colder temperatures while trying to argue that you were right to argue the opposite.

simonjames007

DrEskimo said:

1. Those are just estimates. Some EVs can be quite accurate once it gets used to your general driving habits, but I never knew of any petrol car that did a good job on estimated range. Wouldn't pay much attention to them and certainly not indicative of a major fault.

2. The range seems comparable to other users in the colder months. How much were you expecting?

You don't have an option to simply hand back for a refund. You need to give the dealer a reasonable chance to fix the issues, so would get it booked in and can sort out most of those minor issues. If the error message persists, then you can think about escalating it.

When driving locally for 2 miles it used up almost 6 miles of battery, only fully charges to 19 miles.

macman said:

Did this 4 to 5 year old car not come with some form of additional warranty? Dealer, based, insurance based, or even 'BMW Approved' or similar? i'd expect something of worth on a vehicle that could be little more than a year out of manufacturer warranty.
The slow puncture could well have occurred during your week of ownership, but they've offered to fix it anyway.

I purchased additional 3 year warranty. 
The low pressure warning light came on after 5 miles. Yes it could have happened within the 5 miles with a nail. I will see when i I go to get it fixed. 

diystarter7 said:

Hi

If the dealer takes the car back, will you be buying the same make/model?

Yes if they have the same car for sure.

The car is booked into BMW for an hours diagnostics check lets see what the results are.

Stateofart

Yes fuel and especially battery life will certainly be lower with age AND the cold.  Sometimes almost 50% less.  Do your research !  Condensation in headlamps/brakelights is v.v. common and a reason why some have small holes in the glass to allow the condensation to escape.  Could be a puncture, could be the TPS - another v.v. common problem.  I have this issue on both my cars.

DrEskimo

simonjames007 said:

DrEskimo said:

1. Those are just estimates. Some EVs can be quite accurate once it gets used to your general driving habits, but I never knew of any petrol car that did a good job on estimated range. Wouldn't pay much attention to them and certainly not indicative of a major fault.

2. The range seems comparable to other users in the colder months. How much were you expecting?

You don't have an option to simply hand back for a refund. You need to give the dealer a reasonable chance to fix the issues, so would get it booked in and can sort out most of those minor issues. If the error message persists, then you can think about escalating it.

When driving locally for 2 miles it used up almost 6 miles of battery, only fully charges to 19 miles.

Not uncommon. Actual range is so dependent on driving style and weather. Worth getting it checked given the error message, but this on its own is not necessarily a sign of a fault. Just reality of plug in hybrids and battery efficiency in cold weather.

If it's like other EVs I've driven It will adapt to your style of driving and be more accurate over time. Still expect fluctuations as the seasons change though. Probably get about 15-20 in winter and 25-30 in summer months.