This is not a post directly about the weather! but I was up at 6am this morning (about an hour earlier than normal) and went to meet a man about a gearbox (with concentric hydraulic clutch )..

It was cold and after removing the frost/ice from the windscreen and warming up the engine it didn't half seem to pull well with the nice cold air maybe it was just me.

Anyone else noticed their cars (locost or other) liking the cooler oxygen dense air in the mornings/evenings?

Ned.

My scooby loves the cold weather!

As far as I can recall, all i.c. engines like cold air - the petrol charge can get more volume expansion than from warm air.

This is why diesels often have intercoolers between the turbo and the engine - the air gets heated in the turbo and needs to be cooled for maximum efficiency. Or something. Or I may be talking complete drivel. Your call!

chrs,

David

All engines like cold, dense air! Prob more noticeable on engines with IC. You'll notice the difference at the top of a mountain with the thin air sapping power.

They must really like it if you want to tell us twice!!

It's amazing the difference a few% makes to the feel of a car.

Has anyone tried Shell Optimax Super Unleaded? It's got a higher Octance rating than normal super (and helps clean all the poo out of the engine). I use it in my Golf V5 and it gives the same sort of extra response you get on cold mornings.

PS. My doors were frozen shut this morning never mind the windscreen...

Andrew

Always run with optimax, not sure it makes a "real" noticeable performance difference, but mentally it seems faster!!

I definetly get better mpg than standard unleaded though.

[Edited on 21/10/03 by MK9R]

[Edited on 21/10/03 by MK9R]

Yeh, I get something like 5mpg better than with normal fuel. Makes up for the cost difference.

EVO mag did a test using a number of different vehicles. They did lots of performance times and then ran them on Optimax for a month. The theory being that not only will the fuel make it better a months cleaning would help.

They had an M3 that had been run on nothing but Supermarket fuel and after a month was 1 second quicker to 60!!

Andrew

one of the few things i learnt during my mech-engineering degree is that the amount of power a motor makes is determined by the temperature difference of gases before/after combustion. so there you go, that's why mr diesel invented the intercooler.

Isnt the air cooled so you can squeeze more air/fule mixture in the cylinder especially with a turbo because cold air takes up less volume than warm air?

cold air is higher/more dense in oxygen, hence burns better.

Ned.

cold air is just denser, doesnt affect O2 % but does mean that you'll have more air, and therefore more O2 in your cylinders, and therefore more go go juice as well - hence more POWER!!!!

I have read that if you fill your tank on a frosty morning, you get 5% extra fuel due to the petrol being cooler and therefore more dense

hi and welcome!

please use some of your degree experience to downsize yer avatar pikkie!




atb

steve

quote:

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Originally posted by aus-sambo
one of the few things i learnt during my mech-engineering degree is that the amount of power a motor makes is determined by the temperature difference of gases before/after combustion. so there you go, that's why mr diesel invented the intercooler.

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Probably, but its driver doesn't. They do run better on moisture laden air in the morning when the engine has warmed up.

yours, Pete.