Saabotage 9-3 Aero 2.8t Goal!

[NateHale88]

Hi all, haven't posted in awhile. My current work commuter car is a 08' Saab 9-3 Aero 2.8T V6 DOHC rated at 280HP/300TQ. EPA is 16 city and 26 Highway.

As usual I find these EPA numbers to be vastly underrated. The car is incredibly fun to drive with the turbo and being a manual transmission. I do not regret buying it at all. I consistently get 28.5+ MPG average(93 octant) with 'spirited' driving.


I decided I am going to for the hell of it see just how good I can do with a bit of Eco driving. I am shooting for a 500 mile tank(16 gallons) as my first goal.I have a current high of 477 miles. My next goal will be to see if I can push it to a 600 mile tank. For this I will need to incorporate more of my Eco Driving skills and do some EOC and try and avoid boost as much as possible.

I just filled up with 89 Octane yesterday and from my 32 mile home-work commute I was able to average 35.6 as per my gauge. This will go down and average out more as I put more miles on it but was a very good start.


Wish me luck! Any tips will be appreciated :-).

[deejaaa]

speed is what kills mine. I use an ultragauge. if I can get the average mpg high in the beginning, it's easier to maintain, verses trying to catch up from a low beginning.

[rumdog]

Good looking car there, maybe block some of your grills while the weather isn't too hot... the two out side ones or top? Easy to hide on a black car

[oldtamiyaphile]

Originally Posted by NateHale88

For this I will need to incorporate more of my Eco Driving skills and do some EOC and try and avoid boost as much as possible.

Be careful EOC'ing with a turbo, you might damage it. I personally don't EOC my turbos.

[BabyDiesel]

Originally Posted by oldtamiyaphile

Be careful EOC'ing with a turbo, you might damage it. I personally don't EOC my turbos.

Oldtamiyaphile has a good point. I personally would try EOnC before EOC and see what difference that made.

[Arragonis]

Originally Posted by BabyDiesel

Oldtamiyaphile has a good point. I personally would try EOnC before EOC and see what difference that made.

+2 - shutting off the engine also cuts oil to the turbo which can affect the coolling. If the oil remains it can boil and weaken seals or leave deposits there. Neither is good.

[NateHale88]

Yeah, that does make a lot of sense. I think I will refrain from the EOC.

I already do a decent amount of Engine on Coasting.

Curious tho what is the difference between going EOC and just shutting the car off after you are parked and done driving? I have noticed that if I am really getting on it a lot that the car has its own sort of turbo timer high speed fan cycle after I turn it off.


Thanks for the tips guys! Plans are also to get a Stage 1 Tune to bump up the HP/TQ and according to most reviews this bumps up the MPG nominally(1-2mpg observed). Not saying its a guarantee but worth it for more enjoyable driving to me :-).

All in all she doesn't do too bad for a DOHC Turbo 6 cylinder that weighs a boat load!

[Arragonis]

There were a number of early turbos here (UK) which suffered when owners pounded them down the motorway at 90+ and then shut them off to have a coffee at a service place. The advice was to let it idle for a minute or so before shutting off. Also that last gasp rev before shutting off thing, not good - petrol anyway.

[oldtamiyaphile]

Originally Posted by NateHale88

Curious tho what is the difference between going EOC and just shutting the car off after you are parked and done driving? I have noticed that if I am really getting on it a lot that the car has its own sort of turbo timer high speed fan cycle after I turn it off.

The main difference is if you P&G, it's high load followed by a shut down, that's bad news for the turbo. As a rule, as long as the engine is driven off boost for the last mile you're OK to shut it down. I'll sometimes do an EOC if for example I've just descended a nice long hill and I know the turbo has had a chance to cool.

Modern turbos are very good and some people routinely EOC them. Just keep what's been said above in mind if you do.

Some cars will run their radiator fans for a while after shut down if they're really hot. This isn't to do with the turbo more to prevent heat soak under the bonnet.

It's also possible to modify a turbo car for P&G EOC by fitting an external oil pump into the oil supply line.

[NateHale88]

Just an Update:

Day 2.5 of the 500 mile tank challenge. Everything is going pretty good so far, sadly I had to make a trip to go look at a car on a significantly less economic route as per my usual. But I was still able to maintain an average of 32.2 for the 160 miles so far for this tank.

Hoping with my home commute today I can bring the average up a tad. Been doing some mild neutral coasting to the stop signs and trying to keep it around 55mph(my route is mainly back country roads).


So far so good! On track to hit my 500 mile goal with ease. Time will tell! Cold weather here has made it hard with most mornings in the 30's. Great for performance, bad for mpg haha.