February 2004
Flicking through a car brochure the other day , comparing fuel figures for the same model car, one fitted with 1.8L, the other 2.5L
It was apparent that the 2.5 returns, nominally, a good 10MPG less than the 1.8.
Lets say both of these cars are travelling at a constant speed, side by side along the same bit of road. In theory, both engines are having to do the same amount of work as the cars are the same shape & mass. Where does the 10MPG go?
OK the 2.5 may have slightly higher frictional losses but 10MPG?!
Are small engines more efficient in terms of converting fuel into work?
OR is it then because the swept cc volume "per metre of road" is higher in the 2.5 because the gearing hasn't been reduced in proportion to the increase in available torque? (I suppose if they did that the 2.5 would offer no performance advantage over the 1.8)
So, is the conclusion that larger engines are both less efficient and intentionally "undergeared"?
Perhaps this is all a load of tripe and someone out there will know the solution!?
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I see from the ads. to the right of the backroom that there is a new haynes manual. I won't use the word in case it gets filtered ;-)
Anyway a couple of points come to mind ;-))
1) Does it use the phrase 'refitting is the reverse of removal'?
2) What does it use instead of spanners to indicate the difficulty of the 'job' so to speak?
Sorry I'll get back in my box now.... Read more
..and re-boring (sorry). Oh dear - aren't we predictable...
One for the FAQ I think.
I was trying to find out the insurance groups for several cars, tried C-by-C breakdown, HJs FAQ and the various manufacturers websites without any luck. Then did a google for 'car insurance groups' which yielded lots of info.
These are set by the ABI for UK cars and they have a very useful
search engine for finding the insurance groups of current model cars. I wanted to do some research about possible cars to replace the volvo including the likely change in insurance costs.
www.abi.org.uk/carinsurance/search.asp
hope that somebody finds this useful, perhaps HJ will add this to the FAQ
Ian Read more
I use www.parkers.co.uk to find insurance groups of various cars (insurance group being a major issue at 21), it's very good and easy to use, bar the occasional strange anomalie
I understand from another poster that catering oil can contain a flame retardent. Can this effect ignition and reduce efficiency? Read more
Hi Pullgees. I run a Pug 309D on new and used veg oil. I would esitimate that there's probably roughly a 10% drop in power in both cases. I believe the reduced power is a result of veg oil's naturally lower cetane value - diesel's equvalent of octane. Veg oil has a cetane roughly around 42, whilst diesel is over 50, depending on who's fuel you buy. The reduced cetane means you need to burn more oil to get up steep hills etc!
I boost the cetane rating by the addition of around 0.5% by volume of 2-ethyl hexyl nitrate. A fancy name for a chenmical that's widely added to diesel by manufacturers to boost the cetane rating. It's not a cheap substance to buy, so there's a cost / performance trade off. After a bit of experimenting, I get around 50mpg, at a cost of around 57p/litre (if using new oil), with slightly better performace than dino-diesel.
Does anyone have a source for VAG210 a Cambelt tensioner tool?
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Circlip pliers do the same job..
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groups.msn.com/honestjohn - Pictures say a thousand words.....
Hi,
does anyone know of anywhere in the Southampton area that will hire a Transit type van to a 21yr old?
I know its cheeky, but im at work and cant surf the net all day searching - though a quick look and most places only hire to over 23 yr olds (easy car/Budget etc)
I only need it for a day - girlfriend's gonna be movin house... deep joy!
cheers,
Dave Read more
Fair cop,
Realised that a second after i hit "Post this Message" actually, sorry!
Congratulations for surviving last night without your loyal and hard-working moderating staff.
We were conducting a quality survey of Braksepars bitter in a fine hostelry in Oxfordshire.
Not that the evening was without difficulties;
The Pub that No Dosh had arranged for us to meet in had burned down, reopened, closed down and offered for sale all within the last couple of months.
We had to wait outside for a while waiting for DD. The AA Man left disappointed when he realised that ND wasn't going to risk switching off his Alfa and trying to turn it on again.
The pub we did find had little or no parking but was a very pleasant little pub. A little out of the way as I realised when I left the pub and an Ambulance from Abingdon stopped to ask me the way to the M40. We were a LONG way from Abingdon. Although I did check that they hadn't arrived just to give DD a lift home.
Some people commented that one of the moderators smokes quite a lot, but he didn't pay any attention to the whingers, particularly since once of them spends his time irradiating the country and the other was always an awful car salesman anyway.
We did think David Brent had turned up, but ND says that people are always saying that.
We had a group check of the fog light switch on Dave's cavalier and it is where he says it is and you couldn't switch it on accidentally.
And we discussed you lot - and that was probably the most fun of all !!! Read more
HF - If I didn't have to go to work tommorow I would be there, I'm in the mood for a road trip! :-)
Blue
In today's Metro NW edition there is a story on how dirty number plates can cost you up to £1000 and it is a quote by a Chief Constable. Also he says how one in three motorists are unaware of this rule.
I am one of "middle england" and I can't believe such a penalty which is out of all disproportion to the "offence" and also that a CC takes time to actually talk about it when there are IMHO other more pressing issue like uninsured and untaxed drivers etc.
Is this just me or what do other BRs think?
What next? Sorry sir your car has not been cleaned for a week? That will be £XX. I know I am taking it to extremes but I just wonder sometimes where the priorities are and again this is an example of hammering the honest motorist. Read more
No, we'll have rfid chips.
Hi guys.
Got my sisters car to service now and i was hoping someone in the know could tell me what the minimum brake disc thickness for this model is? it's a 1998 1.1l saxo.
Cheers
Richard Read more
Not sure if this applies to other cars, but according to the Haynes manual for Vauxhall, if discs are 10mm new, replace them at 8mm. If 20mm new, replace at 16mm, etc, etc.
Browse
So how come, (unless this has been answered above and I missed it or didn't understand it!) a 14 litre diesel Scania hauling 40 tons can do about 10 mpg, my 2 litre diesel doesn't do 70mpg despite hauling only (very roughly) two thirds the weight per cc? In which case it should really, in proportion be doing about 100mpg.
And don't tell me the aerodynamics of a Berlingo are worse than a Scania (even if they are!)