bhvrdr

you cannot put heat soak issues aside. They are a huge factor in performance loss for all automobiles.

Most drivers do not mind a slight performance loss in hot weather and many do not even notice the performance loss. The A4, on the other hand, is much more susceptable to these losses. If you look at the article it clearly states that just running on premium fuel did in fact help some of these cars. The mustang gained 2hp and the Dodge 3hp. Keep in mind that the tests were run on a dyno (presumably with fans), which does not at all mimic stop and go traffic or summer afternoon drives. Imagine how much MORE the results would have favored octane increases would they have tested in those conditions...not to mention on turbocharged cars.

Next the author's tackle the cars that require premium fuel (just like our A4 turbos):

The authors state:
The results were more dramatic with the test cars that require premium fuel. The turbocharged Saab's sophisticated Trionic engine-control system dialed the power back 9.8 percent on regular gas, and performance dropped 10.1 percent at the track. Burning regular in our BMW M3 diminished track performance by 6.6 percent, but neither the BMW nor the Saab suffered any drivability problems while burning regular unleaded fuel. Unfortunately, the M3's sophisticated electronics made it impossible to test the car on the dyno (see caption at top).
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Funny how C&D swithed to percentages when reporting the losses, huh? Maybe if it's because stating a 9.8% loss in the saab is not as harse as admitting that it means the saab lost 22hp (engine is a 2.3l turbo at 220hp) in a temperature controlled room on a dyno. So is it throwing away money spending $5 on a gallon of Toluene to gain 5 or so horsepower and prevent the loss of 15-30hp in hot-weather conditions?

It's is a waste in C&Ds opinion, but certainly not for an enthusiast. People spend $500-$700 for 10hp gains chipping the 3.0s. $5 is a bargain. Cheers! Mike

KenK in TX

...and I guess worth is subjective.

Like I said, I don't own a 1.8T. I do live here in Houston where its crazy hot and humid, and the only time I've ever heard 1.8T guys complaining about heat soak (and preformance loss) is after they've run the **** out of the car (race conditions) or they've been crawilng in traffic for hours with the A/C on in 100+ degree weather.

Thanks for hanging in there and explaining it.

I didnt realize the 1.8t fell on its face and pulled back timing every time it's driven, so I see your point now. If I were in that boat, I'd be pretty pissed off - but I'd also probably spend the $5 to prevent it from happening or do something more permanent like an intercooler.

bhvrdr

It's a pain. Oh well. I'm looking at a FMIC solution, but fact is that the K03 and K04s just run sooo hot. Bolting on a bigger Garret or BW turbo actually lowers the turbo temps. Take care, Mike

Audi Junkie

Don't forget, to determine real cost, subtract $2.25/gallon for the gasoline that it replaces ; 0 )

jgoot

am I not buying enough? Do I have to order a 55 gallon drum?