34 replies to this topic

[GazT4R]

Lord B, on 27 January 2012 - 09:57 , said:

They recon in short term difference in price between Petrol and diesel will grow, as when most refineries were built, there was little demand for diesel and everyone wanted petrol, petrol refineries cant be converted to diesel, so lots of diesel is imported, and petrol refineries have excess capacity, possibly why coryton refinery has gone into administration

seems amazing that something like a petrol refinery can make a loss of 400 odd million quid

I'd love to buy more and help out but the robbing bastards called 'the goverment' are rinsing us and the industry bare.
Given the massive amount of tax on fuel I'm not that surprised when you consider they dig it out the earth, transport it, refine it, transport it again and then sell it for far less than bottled water per litre and then the government takes approx. 60 ppl in tax and no doubt taxes the businesses themselves too .
Actual fuel cost is about 70ppl to fund the entire supply chain, reasonable considering the costs involved.

[Engineer]

Specification and operation of the BMW Tri-Turbo:
Automotive Engineer

The answer to those querying petrol engine development well its direct injection with turbos using lean burn stratified combustion for economy and homogenous combustion for power with a combination of the two on cross over at present.

All petrol engines are of this type now otherwise they would not not meet EU emissions, they are between 15% and 20% more efficient, I even have a few at work for training purposes!

In a nut shell a 1.6 engine will give 2.0 performance and a 2.0 will give 2.5 performance.

A good article below describes these types of engines being used in the WRC by various manufacturers.
Automotive Engineer

The Ford Eco-Boost WRC engines are a good example as the 1.6 engine using a 33mm turbo inlet restrictor is expected to produce @ 300 bhp at 2.5 bar boost using fuel injection pressures of @ 250 bar.

All BTCC engines AFAIK will also be petrol direct injection turbos as well.

[GazT4R]

That's good news Gary on the petrol front, was about time the game started moving forward given the current state of play with diesel/petrol prices and demand/supply.

[JezF]

Exocet - never had HGF myself but my car had it at 60k miles, now at 100k with revised gasket and metal dowels. It's a good engine design save for the HG issue though.

Neither my  sc Honda or Audi engined cars have had HGF - surprise surprise!

[Exocet]

It's only a matter of time with the K series! But yeah, other than that it's a cracking engine. The metal dowels were so tight they needed to be reduced a few thou before I could get them in. Vastly different from the plastic ones which were incredibly loose.

The old gasket still decorates my garage wall

[T5-Andy]

I can't help but think that cars with engines such as the triple turbo beemer are fine well and good providing you buy them new and dispose of them before the warranty runs out because if you don't then no matter how economical they are in terms of fuel consumption, the first time you have a problem with one of those three turbos or the associated plumbing, control gear and/or gadgetry you're gonna find out just how much cheaper it would have been to just run a petrol! Although I will qualify that with the cautionary tale of the purchaser of a VW Pheaton W12 who found he had an issue (don't quote me on this but I believe it may have been a cam timing issue (cam chain???)) the solution to which was a "remortgage the house" job, so not just diesels that can become so over bloated with technology as to be of limited use outside of warranty period! Better of sticking with an old Volvo methinks!

[JezF]

Andy, a few people have commented on how cheap V8 Audi RS6's are. Mate owned one from new and he said it cost twice as much as his DB9 to run!

Agree, if you have disposables then fine but otherwise keep it simple. Just impressed with the technology that can deliver this performance allied with low CO2 and emissions.

[Sir Drivealot]

Around town the diesel is definately an advantage, but on long runs with a load on board and at about 80mph I really don't tell much diference TBH.

I've driven Peugots, Nissans, Mercs, Fords VWs, and Vauxhalls (all diesel) and never managed to get above mid 30MPG with a boot full of tools, and a deadline to meet. I can get 32MPG on the same kind of run with a 2.4 T5.

I even got 42mpg average driving in Holland at an average 65mph in the T5.

Around town though it's back to 23 to 25 mpg.

[Sir Drivealot]

Upkeep on the diesels is massively more expensive, there are so many "clever" systems on them that it's a bloody nightmare.

Prices of Particulate filters, and other parts of the emissions systems is eyewatering.

[JezF]

Sir Drivealot, on 29 January 2012 - 19:08 , said:

Around town the diesel is definately an advantage, but on long runs with a load on board and at about 80mph I really don't tell much diference TBH.

I've driven Peugots, Nissans, Mercs, Fords VWs, and Vauxhalls (all diesel) and never managed to get above mid 30MPG with a boot full of tools, and a deadline to meet. I can get 32MPG on the same kind of run with a 2.4 T5.

I even got 42mpg average driving in Holland at an average 65mph in the T5.

Around town though it's back to 23 to 25 mpg.

Depends on the engine size though.

Wife's Fabia - 165bhp/275lb torque - 55mpg on a run and a fairly easy 40mpg round town. 75,000 miles and no engine issues, leakiy rad, two wheel bearings and two brake caliprs replaced though.

[V70Ben]

Try.with a boot full of tools....

[tingymagig]

id be willing to bet my D5 fully loaded would give me better mpg over a long run then my T5 empty

in fact i will even test it on the way down to the track day as they will be in convoy and most of the weight is going in the D5

[GazT4R]

tingymagig, on 29 January 2012 - 21:09 , said:

id be willing to bet my D5 fully loaded would give me better mpg over a long run then my T5 empty

Not really the best comparison there Aiden.
Facelift D5 with one of the later engines and a far older petrol turbo.
Given the disparagy in values you've already proved the petrol was cheaper to run over an average 12k year before you start .
I do see what your getting at and no doubt the diesel will give better mpg, although sat at a reasonable speed, good vacumn, it should close the gap on the oil burner.

A better comparison would be with a 2 litre turbo petrol since that would give closer performance to the D5. We know that a T4 driven reasonably well can return near 40mpg if not over on a run, the weight of a V70 shell would only be around 100-150kg more which would equate to a few mpg, a lot closer to the D5 mpg.

It's given that on the whole diesel is more efficient than petrol, hence diesel is used in trucks, trains etc. however with the improvements in petrol technology and the increasing price of diesel plus the higher servicing and purchase costs of diesels the gap is shrinking, quite rapidly. Will it ever close, I'm not so sure that remains to be seen and largely depends on development of new fuels and the price of current fuels.

Fifth gear did a small test of a diesel small car and petrol model both specced the same over a set circuit, urban and open road, with the same driver. Nothing scientific just a fill to brim, drive and then fill to brim.
The small petrol was more fun to drive, observation of the driver, and beat the diesel by several mpg plus cost less to buy and service.
Nothing conclusive however do beg the point that are diesels that much cheaper to run per given output? Maybe not, a lot of variables depend on what the car is used for.

Edited by GazT4R, 30 January 2012 - 18:09 .

[tingymagig]

GazT4R, on 30 January 2012 - 18:06 , said:

Not really the best comparison there Aiden.
Facelift D5 with one of the later engines and a far older petrol turbo.
I do see what your getting at and no doubt the diesel will give better mpg, although sat at a reasonable speed, good vacumn, it should close the gap on the oil burner.

its as fair a comparison as this - and a reasonable speed was not preposed 80mph was preposed

Sir Drivealot, on 29 January 2012 - 19:08 , said:

Around town the diesel is definately an advantage, but on long runs with a load on board and at about 80mph I really don't tell much diference TBH.

I've driven Peugots, Nissans, Mercs, Fords VWs, and Vauxhalls (all diesel) and never managed to get above mid 30MPG with a boot full of tools, and a deadline to meet. I can get 32MPG on the same kind of run with a 2.4 T5.

I even got 42mpg average driving in Holland at an average 65mph in the T5.

Around town though it's back to 23 to 25 mpg.

they are both 5cylinder engines, they are both within 100cc of each other, they are both mapped

also the T5 has much more stacked in its favour its not an auto, it weighs less unladen, no DPF (and its already been proven the 185 engine is not the most fuel efficient engine compaired to the 163 so if my D5 does beat it then a manual 163 would whop it mpg wise) and the D5 will be loaded to the gills

GazT4R, on 30 January 2012 - 18:06 , said:

Given the disparagy in values you've already proved the petrol was cheaper to run over an average 12k year before you start .

nope i predict by the end of this year the T5's 5000ish miles will have cost me a lot more then the D5's 12000 miles and you can pick up D5's for the same price as i paid for the T5 now

GazT4R, on 30 January 2012 - 18:06 , said:

A better comparison would be with a 2 litre turbo petrol since that would give closer performance to the D5. We know that a T4 driven reasonably well can return near 40mpg if not over on a run, the weight of a V70 shell would only be around 100-150kg more which would equate to a few mpg, a lot closer to the D5 mpg.

i dont know how quick you think my T5 is or how slow you think my D5 is but i disagree a 2litres performance is not closer to the D5 tbh below 70mph there would very little in it performance wise between the 2 cars as they are now, and the T5 would only really start to show the D5 a clean pair of heals above 100

[GazT4R]

Ok Aiden, you have fun.