Hot weather; who else's MPG has been down?

[Ally_bassman]

As above, with the recent heat wave we have been experiencing, my MPG has been down by a good 5 MPG's. Doesn't sound a lot, but I do a fair few miles!

Who else has noticed a difference when the temp has been over 25 degrees C?

[newbie69]

Normally when Spring arrives it's the other way round for me, at least the very first 10 KM have 20-30% better mpg figures due to the car getting to temp quicker. Then as you move into Summer and if it's a hot one, the A/C works overtime so I guess you're referring to that? Not worse than winter though I'd say although I don't monitor my consumption closely, i find it fine plus-minus a few mpg for such a car.

[Ally_bassman]

I try not to use the AC, maybe for 10 mins of my journey, I'm just interested to hear other peoples thoughts. I get the same figures in the morning when it's cool, but on a hot drive home it's down on normal.

[OzFabia]

25 degrees hot? :no: 

[Ootohere]

Is this with a Tuning box on an a Bigger Air Intake sucking that warmer air in.?

Maybe something to do with the big change in MPG.

 

Worth checking the tyre pressures when the ambient temps are high.

 

george

[Jabozuma]

My MPG actually improves summer time. But this is marginal and 99% depends on my driving style, everything else is too marginal to consider for me - I boot it more than once on my 20 mile trip from work and it drops below 30mpg. I drive like a nun and it goes back up to 40mpg-45mpg

[pee81]

My mpg goes up with the hot weather

[Furbytom]

My MPG has been pretty decent recently too. My CAVE car used to drop mpg and also noticed a significant performance loss in hot weather but this CTHE seems to be loving it lol!

[MidlifecrisisT]

I've not really noticed a difference in mine at all dude. Still averaging the same. Mine is cave too.

[Ally_bassman]

Got 39 on my way home compared to a usual 43 with similar traffic. I used the air con for most of the way. That could be affecting it?? Or like George suggested, my metal ITG and TMC box?

[Ally_bassman]

25 degrees hot? :no:

Hot for us lot! Was 28.5 on my drive home just then! :SUN:

[the mad monk]

i find the hotter weather makes me drive just the little bit quicker so my mpg is down too :( but my fun is up

[Outofthi5world]

My last fuel up was 3.7 MPG up on my average at 40.1 MPG which has only ever been matched (almost) on 27/4 with 40.09 MPG but then I had a trip to Costco. I'm going to fill up right before and right after I go to Alton Towers on Monday (and if I need fuel down there fill right up, record and try to find a Tesco fuel station)

[iSamage]

Mine's on the up. But probably because the engine is loosening up. 8k in five months!

Oh was this a vRS thread? In which case my dad's car is sitting pretty much unused with 3/4 tank and "130 miles" range!

[devonutopia]

Mongrel gives awesome economy in the heat.  I guess this is because there is less warm up time.

[Toxicvrs]

Mine was down to 27 found out there was a hole in fuel filter now up to 52

[jonro2009]

Mine has dipped by maybe 2mpg I have also noticed it is a little more sluggish in 2nd at low revs

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[Ally_bassman]

Thanks for all the replies lads, no it's not a VRS thread, I wanted to hear everyone's thoughts :-)

Interesting that people are seeing gains, I'm going to start monitoring it a little closer.

[OzFabia]

Hot for us lot! Was 28.5 on my drive home just then! :sun:

 

Try this. 

 

 

 

In all seriousness, I think it might be your using the air con. I find the car warms up more quickly to the most economical running temperature in hot weather. That said, after an hour in 35 degrees plus conditions, I get (presumably heat-soak caused) loss of performance.

[mattgirling]

Mine hasn't changed... but I've noticed a lack of pulling away power in 1st gear. It might be my imagination though.

[vxh26]

Air conditioning?

Windows open?

[MartynVRS]

Rarely see 30mpg at the moment

[Ally_bassman]

Seems to be a difference in CAVE and CTHE cars. All other TSI, TDI and HTP cars seem unaffected.....

[Ootohere]

Actually the vRS A/C does not make much difference to economy and i have tried and monitored.

 

But with A/C,  it does matter what Ambient temps we are talking.

 

If energy is used, and it must be to a degree,  bringing a 28 *oC  down to 18*oC uses more energy than bringing 22*oC down to 18*oC.

 

But then you can floor the  accelerator a few times and take average MPG of 37 mpg down to 27 mpg on a trip easily.

 

Cars are transport and can be fun, and need to work in all weather.

 

Wet weather & Damp weather even without much wind gives me the lowest MPG in a Twincharger.

(Like for like lowest, ie, Same speed, dry cool, wet cool, or Dry or wet summer weather,

obviously very spirited driving in the dry is the lowest economy of all.)

 

george

Edited 24 July, 2014 by goneoffSKi

[Jabozuma]

Mongrel gives awesome economy in the heat. I guess this is because there is less warm up time.

What, the 370bhp mongrel gives awesome economy?