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Re: RE: Re: hey guys does this seem fair?

Posted: Sun Nov 08, 2015 4:47 pm
by danarama
JayDKirk wrote:I always thought a hot engine run better than a cold engine as that's why cars get better mpg on long runs? Or am I just loseing the plot here lol
I think the point is that the mpg you will lose by heating up the engine for 10 minutes parked up would be more than the mpg you would use by running the car cold and letting it warm up whilst driving.

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Re: hey guys does this seem fair?

Posted: Sun Nov 08, 2015 5:25 pm
by Mr Tuscan
Exactly!

Engines run best when at operating temperature.

The reason engines get better mpg on long runs is because they are usually on motorways so less changing gears , less stop start and generally better average speeds the ideal speed being around 56mph, although that last part was based on cars from years ago so that may be a little different, that is the reason for better mpg not so much the cold engine part although that has some bearing on it but most cars are at operating temperature within ten minutes of driving, sitting with the car at idle it will take longer than ten minutes and all your doing is burning away you fuel.

As has been said before and from what you keep posting, you could learn a hell of a lot from this group judging by some of your posts, your not loosing the plot you just need to get off the 100mph train, slow down, take on advice and learn what's best from a field of knowledge and old age experience that is on this forum :handgestures-thumbupleft:

Re: hey guys does this seem fair?

Posted: Sun Nov 08, 2015 5:29 pm
by danarama
Another mpg tip is change gears at lower revs, if that's not too obvious ;)

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Re: hey guys does this seem fair?

Posted: Sun Nov 08, 2015 5:31 pm
by s4mc0x
But not too low, straining the engine is worse for fuel!

Re: RE: Re: hey guys does this seem fair?

Posted: Sun Nov 08, 2015 5:37 pm
by danarama
s4mc0x wrote:But not too low, straining the engine is worse for fuel!
Well, as low as acceptably possible..

Basically don't floor it and avoid the loud.

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Re: hey guys does this seem fair?

Posted: Sun Nov 08, 2015 5:40 pm
by foxfeeder
JayDKirk wrote:I always thought a hot engine run better than a cold engine as that's why cars get better mpg on long runs? Or am I just loseing the plot here lol
A hot engine does use less fuel than a cold one, BUT not to such an extent that letting it sit for 10 minutes burning fuel for nothing will compensate. Additionally, engine wear will be worse, as oil pressure at tickover will be lower, AND there's the issue of someone stealing the car if you leave it unattended. If it's taken with the keys in, you will get NOTHING from the insurance company.

Re: hey guys does this seem fair?

Posted: Sun Nov 08, 2015 10:31 pm
by JayDKirk
I change between 2,500 and 3,000 sometimes ill change at 4k fly its speed up then put in in neutral and let it roll this bad for it or?

Re: hey guys does this seem fair?

Posted: Sun Nov 08, 2015 11:29 pm
by s4mc0x
you're better off keeping it in gear to be honest... fuel wise, it's minimal, but the engine doesn't use any petrol to keep it running as the wheels going round keeps the engine turning, whereas idle in neutral uses fuel to keep going. If we're being really pedantic, then the Highway Code is very against coasting out of gear as you have no immediate control of the car's power.

To be honest, it probably makes little difference, but do use engine braking to your benefit!

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 9:12 am
by paulcounsell
s4mc0x wrote:you're better off keeping it in gear to be honest... fuel wise, it's minimal, but the engine doesn't use any petrol to keep it running as the wheels going round keeps the engine turning, whereas idle in neutral uses fuel to keep going. If we're being really pedantic, then the Highway Code is very against coasting out of gear as you have no immediate control of the car's power.

To be honest, it probably makes little difference, but do use engine braking to your benefit!
:text-yeahthat:

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 10:26 am
by danarama
s4mc0x wrote:the engine doesn't use any petrol to keep it running as the wheels going round keeps the engine turning, whereas idle in neutral uses fuel to keep going.
I did not know that. So the wheels keep the engine turning (which is obvious) but the engine does not take in any fuel? If that is the case, to help me understand the technical aspect of this, when the engine is on it's own momentum, how does the engine decide to take fuel? is that an ECU role?

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 10:30 am
by thedupleman
Plus the drivetrain shock of re-engagement is massive

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 11:02 am
by s4mc0x
danarama wrote:
s4mc0x wrote:the engine doesn't use any petrol to keep it running as the wheels going round keeps the engine turning, whereas idle in neutral uses fuel to keep going.
I did not know that. So the wheels keep the engine turning (which is obvious) but the engine does not take in any fuel? If that is the case, to help me understand the technical aspect of this, when the engine is on it's own momentum, how does the engine decide to take fuel? is that an ECU role?
I don't know how the ECU handles it, my assumption would be the programming simply doesn't pump fuel through the injection system, as there is no requirement to fire the engine. As soon as you put load on the pedal, it'll fire.
Think of it in terms of carburettors, where the vacuum of the engine being turned by the wheels is sucking closed the needle for fuel when the throttle is closed and off the idle jet. If the throttle were open, it'd suck fuel through.
Diesel is different, it needs a constant flow of diesel oil through common rail injectors (albeit much, much less when at idle)

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 11:02 am
by Shel
Many, many, many years ago I worked with a guy who's style of driving involved him coasting up to lights and junctions in fact anywhere he could. His theory was it was cheaper to replace brake pads and shoes than a clutch so why wear it out quicker by changing down. In the 6 years I worked with him he wrote 5 cars off including a new black n gold JPS Capri 2.8i, I lost track of damaged bumpers and lights, he got beaten up twice for running into the back of folk and eventually lost all his NCB on insurance.

How he survived I have no idea but he inspired a whole genre` at work, having an accident became known as "doing a Brian" :laughing-rollingyellow:

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 11:14 am
by danarama
Shel wrote:Many, many, many years ago I worked with a guy who's style of driving involved him coasting up to lights and junctions in fact anywhere he could. His theory was it was cheaper to replace brake pads and shoes than a clutch so why wear it out quicker by changing down. In the 6 years I worked with him he wrote 5 cars off including a new black n gold JPS Capri 2.8i, I lost track of damaged bumpers and lights, he got beaten up twice for running into the back of folk and eventually lost all his NCB on insurance.

How he survived I have no idea but he inspired a whole genre` at work, having an accident became known as "doing a Brian" :laughing-rollingyellow:

To put this in context though, as a new driver, I was actually taught to brake with my brakes when pulling up to a stop, dipping the clutch at the last moment then coming to a stand still. In fact, when I did lessons 10 years ago and again 18 years ago, I was told the same. One of them even said they used to use engine braking because the brakes weren't as good as they are "now".

I use engine braking on hills but I pull up in whatever gear I am in and only change to first / 2nd when I'm coming to a stop or ready to move. if your car is under the influence of the brakes, if you depress your clutch as you're coming to a standstill, they don't class that as coasting. Conversely however, if you're not braking and spin in neutral that would definitely be coasting and possibly even if you're only slightly braking whilst in neutral for a considerable distance.

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 12:55 pm
by Rick
Shel wrote:Many, many, many years ago I worked with a guy who's style of driving involved him coasting up to lights and junctions in fact anywhere he could. His theory was it was cheaper to replace brake pads and shoes than a clutch so why wear it out quicker by changing down. In the 6 years I worked with him he wrote 5 cars off including a new black n gold JPS Capri 2.8i, I lost track of damaged bumpers and lights, he got beaten up twice for running into the back of folk and eventually lost all his NCB on insurance.

How he survived I have no idea but he inspired a whole genre` at work, having an accident became known as "doing a Brian" :laughing-rollingyellow:
Now that's funny :laughing-rollingyellow: :laughing-rollingyellow: :laughing-rollingyellow:

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 1:30 pm
by Mr Tuscan
'Yo Biaaaatch watch me do a Briiiiiaaaaaaaaan'

Re: hey guys does this seem fair?

Posted: Mon Nov 09, 2015 6:53 pm
by Shel
One of the cars was a Humber Sceptre....also wrote off the cement mixer lorry he hit. He walked away without a scratch. Our Brian was legendary in GPO :icon-lol:

Re: hey guys does this seem fair?

Posted: Fri Nov 13, 2015 6:45 pm
by JayDKirk
Don't engine breaking take life of the clutch faster though? Sorry took me ages to reply family problems

Re: RE: Re: hey guys does this seem fair?

Posted: Fri Nov 13, 2015 7:04 pm
by danarama
JayDKirk wrote:Don't engine breaking take life of the clutch faster though? Sorry took me ages to reply family problems
Why, what's the clutch doing in all of this?

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Re: hey guys does this seem fair?

Posted: Fri Nov 13, 2015 7:06 pm
by Shel
Not really, at least if you don't drive like a cross between Ken Block, Lewis Hamilton and Colin McRae :icon-biggrin:

Re: hey guys does this seem fair?

Posted: Fri Nov 13, 2015 7:59 pm
by JayDKirk
I don't hit 3 parked cars lol but when I drop a gear it grunts alot?

Re: hey guys does this seem fair?

Posted: Fri Nov 13, 2015 9:11 pm
by Leonardo
JayDKirk wrote:I don't hit 3 parked cars lol but when I drop a gear it grunts alot?
Sounds like a right pig.