Lewisek Posted July 3, 2015 Report Share Posted July 3, 2015 It's so lovely and warm out there, I'm glad the aircon is so icy cold in these cars. I'll take a dip in power to stay cool in weather like this for sure. 1 Link to comment Share on other sites More sharing options...
SKINY Posted July 5, 2015 Report Share Posted July 5, 2015 Put it this way, if it's 30c outside then with a stock air box, your intake temperature will be around 35c. People with SRI's will be getting intake air temps in the 40s fancy seeing you here lad Link to comment Share on other sites More sharing options...
paulgtt Posted July 5, 2015 Report Share Posted July 5, 2015 God bless the front mount intercooler Indeed but works even better in this weather with a water spray bar Link to comment Share on other sites More sharing options...
slybunda Posted July 5, 2015 Author Report Share Posted July 5, 2015 No wonder they say a Sri improves fuel economy it sucks in the hot air from engine bay. Link to comment Share on other sites More sharing options...
KeoGT Posted July 6, 2015 Report Share Posted July 6, 2015 fancy seeing you here lad Haha, I've been watching my intake temps out of curiosity, I had an intake air temp of 39c before I even started the engine at one point Link to comment Share on other sites More sharing options...
Black Knight Posted July 6, 2015 Report Share Posted July 6, 2015 (edited) Basically Yes, but at a loss of power. I found this which may explain a bit better You might have noticed, driving through the summer months, that you're filling up the car a little less often than you would over winter. It's not your mind playing tricks on you, but a fairly common occurrence for all drivers. Cars simply get better gas mileage during warm weather than they do when it's cold. There are several reasons for that, and we've picked the most relevant ones below. Warm air There's a scientific explanation for why you use less fuel in warmer weather, and it's to do with air temperature. As you may know, your engine uses air, as well as gas, in order to generate energy. In fact, it uses huge amounts of the stuff, though only the oxygen is used in combustion. These oxygen molecules combine with carbon in the fuel during combustion, to form--you guessed it, carbon dioxide. Anyway, one property of air, like many substances, is that it expands when it warms. This makes it less dense--molecules of the various gases are spread further apart. This means that every gulp of air your car is taking during combustion has less oxygen in it at warmer temperatures, and if there's less oxygen, the engine compensates by using less fuel. This is bad from a power perspective, but good for economy. The engine is combusting less fuel due to the warm air, improving fuel economy. During winter, the reverse is true--denser air encourages the engine to chuck in more fuel, boosting performance and harming economy. Interesting idea But don't you think Si that this must be based on a lab style test where exactly the same amount of throttle is applied during each temperature test...in which case yes, the engine may as a whole actually use less fuel. However, in the real world of driving when you think your engine is slightly down on power, or not making the speed you want, the instant reaction is to press the go-go pedal harder, therefore surely using more fuel!?! Edited July 6, 2015 by Black Knight Link to comment Share on other sites More sharing options...
Monkey Boy 1 Posted July 6, 2015 Report Share Posted July 6, 2015 That was my initial thoughts too Iain. But as with a lot of things we do, a few HP here or there either plus or minus would not be noticeable on power, but fuel economy on a run can be affected by a whole host of things. 'Real world' fuel economy is very different to manufacturers figures. For a start the manufacturer does all it's tests in a test cell, not on the open road where things like weather, tyre compound & tread, tyre pressure, wind, Driver & passenger weight, baggage weight, atmospheric pressure, altitude, road surface, age of the car, mileage, service items, driving style etc etc. all have an effect on engines performance & fuel economy. Basically, heavy foot = more fun but less mpg Light foot = boring drive but better mpg Link to comment Share on other sites More sharing options...
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