hard to argue with this ie stop/start use

[E30 325i Rag-Top 2963]

Fuel economy and emissions are directly related, the less fuel you burn the less CO2 and other pollutants you generate. Changing one has same effect on the other.

Emissions is the main driver for the research & development, if you can’t get to the ever lower emissions levels then you cannot sell those vehicles in many, many markets. Lower fuel consumption, or lower running costs (if fuel prices don’t change…), is the positive side effect for the owner.

With the ever lower emissions levels required every single little influencing factor is under the micro-scope, there are no easy ways to reduce even more. For example, RFT produces ever so slightly more emissions than do “normal” tyres.. 

[Neal 546]

So borrowed the wife’s 2017 cx5 diesel today which has istop.

In the time we’ve owned it istop timer was 7.5 hours in 80,000 kms. 

In the last 10000 kms it saved 91kms of diesel so 6.4 litres of fuel or $19.almost immaterial.

However, on the commute home the engine was at zero emissions for. 25% of the travel time.

To me the fuel savings of one tank of gas over the 80,000 kms is neither her or there and any fuel savings will be offset by the cost of a new car battery with the extra start cycles reducing its service life. But the 7.5 hours of zero emissions is worth consideration.

Disclaimer ….. this post used .12grams of carbon.

[Eagle 1669]

Yeah batteries aren't cheap and many people dont understand how to reset the system etc when replacing it so even more cost. In my experience peoples laziness would easy override it too by a long shot. The amount of people who don't even check their tyre pressures for god knows how long is crazy. Let alone any other factors like engine condition and poor driving ability etc.

[kwhelan 241]

11 hours ago, Neal said:

So borrowed the wife’s 2017 cx5 diesel today which has istop.

In the time we’ve owned it istop timer was 7.5 hours in 80,000 kms. 

In the last 10000 kms it saved 91kms of diesel so 6.4 litres of fuel or $19.almost immaterial.

However, on the commute home the engine was at zero emissions for. 25% of the travel time.

To me the fuel savings of one tank of gas over the 80,000 kms is neither her or there and any fuel savings will be offset by the cost of a new car battery with the extra start cycles reducing its service life. But the 7.5 hours of zero emissions is worth consideration.

Disclaimer ….. this post used .12grams of carbon.

not disagreeing with you at all but devils advocate  I guess you times your savings by every other car on the road say in the EU and it all starts to add up personally I think better tech designed around shutting off cylinders would work and mean we could still have powerful cars for when the occasion was wanted, v8s that idled along like a honda jazz around town but still opened up when planted.

[kwhelan 241]

10 hours ago, Eagle said:

Yeah batteries aren't cheap and many people dont understand how to reset the system etc when replacing it so even more cost. In my experience peoples laziness would easy override it too by a long shot. The amount of people who don't even check their tyre pressures for god knows how long is crazy. Let alone any other factors like engine condition and poor driving ability etc.

its never about the money though is it, think the millions your councils have spent on bike tracks,lanes and proposed bridges, rail to nowhere that no one will use,

reseal and straighten a few roads and you would save way more in the long term as a country, traffic that flows is using less gas especially in trucks

[Palazzo 478]

Speed bumps and raised crossings. Force every vehicle to slow down and accelerate again. Multiply that fuel usage out.

I'm amazed nobody has called out Auckland Council for contributing to global warming.

[Young Thrash Driver 1020]

Mazda,s new stop start tech doesn't use a battery or the starter motor. It delivers a shot of petrol and a spark to the appropriate cylinder and away she goes.

[dirtydoogle 383]

3 hours ago, kwhelan said:

not disagreeing with you at all but devils advocate  I guess you times your savings by every other car on the road say in the EU and it all starts to add up personally I think better tech designed around shutting off cylinders would work and mean we could still have powerful cars for when the occasion was wanted, v8s that idled along like a honda jazz around town but still opened up when planted.

Cylinder deactivation is working towards this. I have a 15 year old V8 that has deactivation

And an 87 year old car that does it all by itself on accident 

[lord_jagganath 421]

26 minutes ago, dirtydoogle said:

Cylinder deactivation is working towards this.

 

I have a 4 cylinder airtrek that is permanently 2 cylinders off. fuel consumption is far more, regrettably.

[Neal 546]

Ironically we won a Holden Barina 1.4 a few years back. Drove it to work for a couple of weeks while waiting on m3 parts . Got 6.3 L/ 100 km. Yet the cx5 with a 2.2d does 6.5 L /100 km.  A lot can be said for high torque low rpm running. But suspect c02 between the two would be a large difference.

[dirtydoogle 383]

5 minutes ago, Neal said:

Ironically we won a Holden Barina 1.4 a few years back. Drove it to work for a couple of weeks while waiting on m3 parts . Got 6.3 L/ 100 km. Yet the cx5 with a 2.2d does 6.5 L /100 km.  A lot can be said for high torque low rpm running. But suspect c02 between the two would be a large difference.

CO2 = fuel burned. The old 33kw barina should have always been put in the bin, hateful things 

[E30 325i Rag-Top 2963]

15 hours ago, Neal said:

. But suspect c02 between the two would be a large difference.

As above, CO2 direct link to fuel consumption. Interestingly diesel produces less CO2 for same fuel consumption, so the two cars would be pretty damn close.

[balancerider 770]

On 6/28/2022 at 12:06 PM, E30 325i Rag-Top said:

For example, RFT produces ever so slightly more emissions than do “normal” tyres.. 

Presumably the fact you don't have to carry a spare means a net benefit of RFT's overall on emissions though

[lord_jagganath 421]

i believe RFTs usually have elastomer compounds that are less elastic , due to more being used in them with thicker sidewalls etc, resulting in more filler microparticles being released per km of use vs that of a regular tyre.

[E30 325i Rag-Top 2963]

18 minutes ago, balancerider said:

Presumably the fact you don't have to carry a spare means a net benefit of RFT's overall on emissions though

Only if you put a spare in… most cars without RFTs still don’t have a spare wheel. Mobility kit, can of gunk, etc. instead smaller and lighter!

10 minutes ago, lord_jagganath said:

i believe RFTs usually have elastomer compounds that are less elastic , due to more being used in them with thicker sidewalls etc, resulting in more filler microparticles being released per km of use vs that of a regular tyre.

From what I’ve been told it’s down to the extra weight of the tyre and wheel for an RFT vs non, beefing up the tyre sidewall and rim of the wheel  adds weight, which then increases the inertia requiring more energy (ie fuel) to be used to get it moving.

Same reason the wheel bolt PCD has been reduced from the tried and trusted 5 x 120 on the new models. Less wheel and hub inertia, less energy, less emissions. 

[Gaz 1061]

7 hours ago, E30 325i Rag-Top said:

 

Same reason the wheel bolt PCD has been reduced from the tried and trusted 5 x 120 on the new models. Less wheel and hub inertia, less energy, less emissions. 

Wheel companies put the pressure on bmw to switch to 5x112 so they didn't have make 5x120 wheels as well. Keeps costs down for the wheel manufacturer and in turn for bmw. 

[E30 325i Rag-Top 2963]

Can’t see that myself, all the BMW OE wheels are exclusive to BMW, so they are tooled up only for the BMW PCD. What that PCD happens to be would make no difference in cost to the supplier or BMW. In fact swapping from 120 to 112 would have added cost in the changeover.

If the same wheels were supplied to a number of brands with different bolt patterns, yes possibly, but that only applies in the aftermarket parts.

[Jacko 2158]

An internet rant I missed

Tyre and brake pad wear produces nearly 1000 times the carbon particulates that exhausts do, and is unregulated. EVs have big ass 20" chromies, weigh a hundreds of kilos more than efficient vehicles that sip on the waste products of dead dinosaurs. 

We need to ban overweight vehicles, like EVs and shitty SUVs, and those running too large a tyres on the back of hatchbacks, to save the planet. Stop start is as irrelevant as taxing chicken farts.

https://www.emissionsanalytics.com/news/pollution-tyre-wear-worse-exhaust-emissions#:~:text=Using a popular family hatchback,a factor of over 1%2C000.

Edited July 2, 2022 by Jacko

[Gaz 1061]

4 hours ago, E30 325i Rag-Top said:

Can’t see that myself, all the BMW OE wheels are exclusive to BMW, so they are tooled up only for the BMW PCD. What that PCD happens to be would make no difference in cost to the supplier or BMW. In fact swapping from 120 to 112 would have added cost in the changeover.

If the same wheels were supplied to a number of brands with different bolt patterns, yes possibly, but that only applies in the aftermarket parts.

Was told that on g20 training, can't remember who took it. But basically said the likes of bbs were tired of having to make specific 5x120 stuff when everyone else in Germany were doing 5x112

[dirtydoogle 383]

3 hours ago, Jacko said:

An internet rant I missed

Tyre and brake pad wear produces nearly 1000 times the carbon particulates that exhausts do, and is unregulated. EVs have big ass 20" chromies, weigh a hundreds of kilos more than efficient vehicles that sip on the waste products of dead dinosaurs. 

We need to ban overweight vehicles, like EVs and shitty SUVs, and those running too large a tyres on the back of hatchbacks, to save the planet. Stop start is as irrelevant as taxing chicken farts.

https://www.emissionsanalytics.com/news/pollution-tyre-wear-worse-exhaust-emissions#:~:text=Using a popular family hatchback,a factor of over 1%2C000.

A Tesla model 3 weighs near enough to a 3 series, and lighter than an xdrive 6 cyl car, most EVs aren't really much heavier than their ICE counterparts 

All new cars are flabby ghastly rubbish

That is an excellent bit of reading though