You can stay out of the boost if you use a light touch on the throttle, but I would say it's typically too tempting to drive with a heavier foot! You're right that there's no gauge to let you know when you're in the boost, but you can hear a faint 'whoosh' sound during acceleration when the turbo is spooling up. I would say that if you drive conservatively and on the freeway a lot, then your gas mileage can average in the low 20s, but most owners are probably averaging in the high teens for MPG.

 

I had a Toyota Supra Twin Turbo stick, in the late 1990's. It did have a "boost" gauge which in reality was a gauge that measured vacuum in the intake manifold as I recall.
One trick I learned is to attain cruising speed, take you foot off the gas pedal, then "pretend" there is an egg between your foot and the gas pedal and ever so gently
apply pedal pressure to maintain cruising speed.

The opposite of this is to stomp or stand on the gas pedal. For sure this will kick in the turbo charger in quick manner.
You will find, probably, that if you are in the upper RPM range of any gear, you will be in the turbo boost mode.
So you could move your gear selector on the auto tranny to the manual mode and get up into the higher
gears quickly. That may work. On my Supra, I used to quick shift and get into 4th or 5th as soon as possible...
for example, 1st, 3rd and then 5th....

Remember, that your engine (with turbo or without) is really an air pump. The turbo takes exhaust gases and spins the turbo fan(s)
which in turn compresses cold air (via a corresponding cold air fan(s)), routes the compressed air to an inter-cooler and then rams that
air into the intake manifold. The turbo's effect or boost has a direct correlation
to engine RPMs and the amount and speed of exhaust gas flow.

I would suspect that an efficient cold air filter (like a K&N) and a cold air box, surrounding the filter would improve both
HP and gas mileage. This modification (filters and cold air box with clear flow air to the box) was common practice in the Supra Turbo
community and was known as "Stage 1" in the quest for more horsepower from the Toyota straight 6.

Does anyone know if there are oil lines going to the Volvo XC60's turbo charger in order to keep it cool and
lubricated?

 

Does anyone know if there are oil lines going to the Volvo XC60's turbo charger in order to keep it cool and
lubricated?

I believe the answer to that is yes, since Volvo recommends letting the T6 idle for a while before shutting off the engine (so the oil can keep the turbo compressor vanes cool while they are still spinning).

 

The basic rules for improving fuel economy are the same for turbo and non-turbo engines:

- Avoid excessive acceleration
- Use high gears and low engine speeds
- Accelerate at a decent pace so that the transmission shifts to higher gears quickly, but keep rpm under 3000
- Maintain a steady speed as far as possible; i.e, avoid jerky acceleration and braking
- Look ahead so that you can use engine braking as much as possible, instead of hard braking

There is no need to worry specifically about boost if you follow the above rules.