Hot day / lose power?

[Tod up north]

I've had my Sonic a little over a month now. I was impressed with the power I was getting from the 1.8 manual, cruising in 5th gear on winding hilly roads and not needing to downshift.
Now that summer temps are hitting (80's-to-90 here in the North) I'm noticing a definite loss of all that power on the hotter days. Leaving town there's a medium sized hill where the speed goes from 45mph to 55mph and when it's cool the car has no trouble accelerating up the hill while I'm in 5th gear; on hot days I need to downshift to get up to speed. Is this a common issue with the Sonics?

 

[spacedout]

Typically above 80F outside temperatures turbo engines like higher octane gas, but If I'm reading correctly you have a 1.8L. Are you now using the AC when you were not before? AC really put a strain on these small engines, definitely loose power vs it being off.

 

[Tod up north]

I use the air off and on, I haven't noticed a correlation to when I have it on and when I don't but I'll pay more attention, thanks.
And yes, I have the 1.8L.

 

[The Champ]

Hot humid air will affect power.

And when you have a small engine without a lot of torque (1.8L has 23 foot pounds less torque than the 1.4L Turbo), you very well could see a loss of power to pull hills in top gear.

Racers have known for decades that a hot humid day will generally end up in slower times and top speeds than cool days on the drag strip.

 

[RMinNJ]

If so a cold air intake should help a little? The best I've seen is whitesmoke hood scoop one.

 

[mitdr774]

A true cold air intake would still be ingesting the same air as the stock intake system. What is available on the market right now (I have not come across a true cold air intake that you can actually buy) will most likely result in higher temperature air being ingested than the stock air intake.

The only reason the 1.4 isnt as sensitive to temperature change is that the computer can command more from the turbo to meet the desired torque levels. If you get rid of that in the programming you will notice the change with weather.

 

[The Champ]

K&N claims a 5 HP gain on a 1.8L with their cold air intake kit.

But....

That 5 HP gain is at 6,000 RPM...

At 2000 RPM (normal cruising RPM), it will have little effect.

Not worth the $273.00 unless you typically frequently run your car extremely hard.

With the 1.4L T, they claim over 7 HP at 5400 RPM.

Moving up to the Camaro SS with a 6.2L - now it's over 18 HP at 5100 RPM.

Or the Camaro ZL1 with the 6.2L - over 25 HP at 4000 RPM.

 

[Tod up north]

It's not worth installing a scoop in my hood. I'll just suffer with the loss of power on those few hot days we have. The winter weather is going to affect me a lot more.

Thanks for the answers!

 

[RMinNJ]

It's not worth installing a scoop in my hood. I'll just suffer with the loss of power on those few hot days we have. The winter weather is going to affect me a lot more.

Thanks for the answers!

Whitesmoke's scoop wraps around the back of the hood so no holes to drill. He have a K&N or
MCFab or ZZP intake then under the hood with heat shield. It seems the best design with outside air fed directly to the intake.

On my stock airbox my UltraGuage shows the intake temp about 5-10 degrees more than outside temperatures usually. But after the car had been sitting it could 20 degrees more.

 

[spacedout]

K&N claims a 5 HP gain on a 1.8L with their cold air intake kit.

K&N can claim whatever they want, if you look closer though their test results are always made with the hood open(colder air) on the dyno, not something anyone would ever do when actually driving the car.

Besides that any gains made will be tuned out by the cars ECU unless you get an aftermarket tune.

 

[bluejay]

i find all cars lose power on hot days not just the sonic but especially ford fiesta ST's

 

[SuperFudd]

Haw does that hotter/ humid air affect MPG?

 

[spacedout]

Haw does that hotter/ humid air affect MPG?

I found with my cruze and now the sonic the 1.4T gets its best MPG when its between 75-85F outside(running premium gas).