Faster With Air Con On ?

[petrolhead]

running phase 1 yaris t sport with cold air induction kit . with all the warm weather had my air con on and the car pulls a lot harder i would of expected it to go slower does the air con do something to the ecu ie more fuel or timing?

[gar]

a/c is gonna burn more fuel when on.. I have read figures stating around 10% but that is on a par with opening windows (due to extra drag) which will slow you down. cold dense air in the airbox will increase bhp a little, on cold dry days you may go a few more mph, hot ones a bit slower without a diff setup! I recon it's just cycle-logical! perhaps as mentioned, you had a/c on, so closed the windows and went a bit faster!

[Cyker]

The aircon puts more load on the engine so it uses more fuel, but this also increases exhaust pressure which makes the turbo spin up earlier; That might be partly why it feels like it pulls better?

(I was reading this thing about some people trying to beat the diesel land speed record, and the driver had drive with the brakes held down initially otherwise the car wouldn't build up enough boost to make it go faster! )

[nickp8]

The t-sport doesnt have a turbo.

[Raeman]

The t-sport doesnt have a turbo.

Not unless he's bolted one on!!

[Yumma]

running phase 1 yaris t sport with cold air induction kit . with all the warm weather had my air con on and the car pulls a lot harder i would of expected it to go slower does the air con do something to the ecu ie more fuel or timing?

It's defo gonna be slower with the A/C on, my T Sport is noticably down on power with mine on (car is fully standard).

The A/C at high cruising speeds can be easily sustained by the higher engine revs and should only have a small effect on fuel economy, whereas having a window open at high speeds drastically increases drag and therefore hits ecomony; whereas conversely at lower speeds and round town the A/C can not as easily be driven by the lower revs and hits economy but as speeds are lower having windows down does not greatly affect drag. So in short A/C is best at cruising speeds and Windows/sunroofs are best opened around town.

As mentioned by others, the standard T Sport is N/A and not forced induction, N/A cars are less affected by warmer temps than Turbos and the like (S/C). Even if you diverted the A/C to your induction air you'd likely sap more power producing cooled air than what you'd gain in engine power from the effect of the cold air feed. This is typical in buildings also where it is more energy efficient to heat a builing in the winter than cooling a building in the summer.

***** don't I go on - Nerd alert!! Enuff said!

[waxxy]

thanks for the info on using air con systems..ive never had one before and my wifes been hammering it..lol she puts it on even if were going to asda and its only 2 mins away no wonder im filling the car up lots lol ill buy her a fan from the pound shop :)

[gar]

Personally, i would rather arrive cool and use a bit more fuel, then arrive steamed and save a few notes, specially if you then waste the saving on cold drinks/lollies!

In my school car, i have no a/c and by the end of the day, i feel drained of energy due to the heat.... i could easily do another hour a day and earn a weeks wasted fuel on a daily basis!!!