Random, anyone getting better economy?

  • Thread starter Thread starter Veero
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Veero

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Last few weeks I notice I have been getting significantly better mileage, 30-40 miles up on a tank. Is this to do with the warmer weather?

The theory I suppose is warmer air is less dense therefore less oxygen molecules per cubic metre, the temp sensor detects this and adjusts fuelling to suit.

But it has only been the last few weeks rather than a steady improvement since winter and my driving has remained exactly the same, also it doesn't feel down on power at all.

Just a random observation really. :rolleyes:

Veero
 
Darren198712 said:
sunny = more girls
more girls = slow down to look :P
driving slower = saving petrol
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That does actually make good sense! :cool:

I've been doing worse money-wise since the price of fuel went up!
 
How much is petrol in the Uk at the moment? Here in Malta is 66.9p, that is 95octane fuel. No other petrol readily available!

I am getting about 38mpg with my N16...
 
ok ok set this straight
just wondering how the hell we are saving petrol. As its hot we tend to use the A/C button so its meant to drink more petrol right

I thorght the cooler the weather the better and more efficient the engine runs. thats why people drag on a nights right ? :confused:

or is this theory correct ? :P
Darren198712 said:
sunny = more girls
more girls = slow down to look :P
driving slower = saving petrol
Click to expand...
 
cooler air, means denser air, meaning more oxygen therefore more fuel has to be used to keep the AFR right.

warmer air, means less dense air, meaning less oxygen therefore less fuel has to be used to keep the AFR right. :)
 
Darren198712 said:
ok ok set this straight
just wondering how the hell we are saving petrol. As its hot we tend to use the A/C button so its meant to drink more petrol right

I thorght the cooler the weather the better and more efficient the engine runs. thats why people drag on a nights right ? :confused:

or is this theory correct ? :P
Click to expand...

LOL.

They generally drag at night so that noone's about...
 
I seem to consistantly get 40mpg in my Si, whatever I'm doing.

however it seems to have come down a lot since putting bigger wheels on ;)
 
mine went down a while ago i think and doesnt seem to have come back up since, but i used to do alot of pointless driving on country roads etc and dont now so i seem to still be putting around the same amount in, just getting less miles from it. o2 sensor is possibly knackered though so once thats done it would be nice to see an increase again.
 
cov_racer said:
cooler air, means denser air, meaning more oxygen therefore more fuel has to be used to keep the AFR right.

warmer air, means less dense air, meaning less oxygen therefore less fuel has to be used to keep the AFR right. :)
Click to expand...
I knew that :P I knew the car ran better with cool air and it had better performance. but I guess it takes more fuel too I guess this is the opposite
 
for general pottering and cruising around, warmer air is better for the car, hence why some cars deliberately draw air in past the exhaust manifold. some older carb engined cars rely on that just to stay going. the venturi effect in teh car can cause the jets to freeze up and block, so you need warm air running through it. my old polo was a nightmare in cold weather!
 
sri_alan said:
My economy went up after I re-adjusted the timing, I got 335 to a full tank on my last fill up
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what is your timing at now alan? think mine's at the standard 15, does the car run better if you advance it to, say, 17 degrees?
 
Its something like 19degrees I think. A normal GTi is 15 +/- 2 so 17 would be ok. I was sure mine wasnt running properly so I adjusted the timing and Id read that the car was rumoured to have advanced timing from the factory, so I assumed that it needed re-adjusting due to its age. I just pushed it till it felt ok, I even took it back to 17degrees and it ran worse than when it was on 19 degrees.
 
ok, thanks Alan :) my car seems to be running ok at the minute, but maybe I'll have a fiddle and see if I can get it to run a bit better :)
 
yeah i noticed this for the last 18 months i have been getting around 270-290 miles to a tank ( with the exception of long motorway runs) however my last two tanks i have got 320miles
 
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