Miles per piddly gallon

[Gerbutt]

The thing I read about the diesel I use(not sure which one not is) is that it's loads cleaner because it's made from gas and not oil, and also has a higher ignition temp so more compression is created before the bang. It's certainly changed the way my van runs, but that could also be due to it cleaning the engine. There is a definite difference if I have to put the cheap stuff in if I'm not near my garage, and I wouldn't have thought that would be due to the engine becoming instantly dirty again?

[Sussex Groundie]

I used to run my smiley Transit on a 10% vegetable oil/diesel mixture, engine ran quieter, better acceleration through the gears, cheap price for the oil (back then).

 

V power out now seems to do the same but also of course cleaner.

[openspaceman]

 

I sort of assume once a vehicle is 7 years or older the 'mpg' will take a hit

 

Mine seems to get better with age I spent about 100,000 miles getting around 63 mpg but now it has 288k miles on the clock and newish tyres my last tank gave 72mpg. I mostly commute 40 miles each way much of it on motorway where I seldom get the chance to get over 65mph. It's a 1.4 tdi in a pug 206. Guys at work with the same engine in fiestas struggle to get 45mpg.

[openspaceman]

The cetane rating on V power is slightly less than bog standard diesel as its less dense . So it does not burn faster . Its just the detergents in it that help stop gummming up of injectors etc . I use standard fuel with Red Line diesel additive .

 

Denseness is related to the carbon content, so petrol is less dense than diesel. As they both have about the same calorific value per kg and petrol has about 90% of the calorific value of diesel per litre I would expect the less dense fuel to produce less heat per litre and less miles per gallon.

[openspaceman]

The thing I read about the diesel I use(not sure which one not is) is that it's loads cleaner because it's made from gas and not oil, and also has a higher ignition temp so more compression is created before the bang.

 

Higher auto ignition temperature would mean it was more difficult to start, do common rail diesels inject more advance of TDC? Detonation is what Rudolph sought to eliminate, he was looking for a smooth burn during the power stroke without knocking. Although of course you want the burn to complete as soon after injection as possible in order for the expansion to take place from the highest pressure.

 

In the old days of slow diesels the aim of the injection was for the burn to take place at constant pressure whereas the burn of a spark ignition engine was aimed at expanding from a constant volume. With modern diesels, especially common rail,the injection is faster, more fine and precise so the diesel has moved toward the burn at constant volume whilst retaining the high volumetric efficiency of not throttling the air supply.

[openspaceman]

I used to run my smiley Transit on a 10% vegetable oil/diesel mixture, engine ran quieter, better acceleration through the gears, cheap price for the oil (back then).

 

 

If it weren't for the LEZ those transits would be my choice for short hauls, easy and cheap to fix. Modern 2.2 TDCI look like they will get expensive to keep past 100k miles.

[Stubby]

Denseness is related to the carbon content, so petrol is less dense than diesel. As they both have about the same calorific value per kg and petrol has about 90% of the calorific value of diesel per litre I would expect the less dense fuel to produce less heat per litre and less miles per gallon.

 

Kinda what I sad then .

[openspaceman]

Kinda what I sad then .

 

Yes, just expanding on it really.

 

We can have an argument about something else:001_tongue:

[Stubby]

Yes, just expanding on it really.

 

We can have an argument about something else:001_tongue:

 

Ok . Wear did you get that shirt ? ! Its bloody awful

[openspaceman]

Ok . Wear did you get that shirt ? ! Its bloody awful

 

What do you expect from the hospice shop?

 

Now where can I get trousers NATO size 80/88/104 that aren't camo so I can wear something comfortable to work?