Trollhattan Saab has changed!
The site you're viewing now is the original Trollhattan Saab weblog, though it's now an archive only and no new material is posted here. As of February 2009, all new material is posted at our new site - Saabs United.
Please join us at Saabs United and get your daily Saab fix from Saab sources all around the world.
TS frequenter and occasional contributor, WooDz, has just sent me a piece on adjusting your driving style to get better mileage from your Saab.
If you’re a little price sensitive when it comes to fuel then here’s a number of things you might want to think a little more on. WooDz has been putting these into practice in his Viggen and has achieved good results.
——
I’ve noticed that a few people have mentioned fuel economy and more recently Kroum and Clive M were discussing their respective results in their Turbo-Xs. I’m experimenting at the moment on how to cut my fuel usage and I thought I’d share a few tips.
A lot of sites have published fuel saving tips and they do offer some valid points. Removing roof racks and stowage boxes when not in use should be common sense. Then there is the driving with your windows shut to reduce drag; another good tip but then they tell you not to turn your air-con on as this is a burden on the engine. Well, one or the other mister! However, as the modern air-con system is far more efficient, I would rather opt for the closed windows and thereby stay cool and focused.
We can go to extremes here and turn off any unnecessary components like headlights and even the radio but I feel there are other ways to get more miles from your tank than sacrificing all your creature comforts. Let’s get one thing straight: Cars use fuel. It doesn’t matter what you try it’s going to be a compromise so you’re onto a loser what ever you choose. This is still about enjoying your driving but also being rewarded by not spending so much time at the pumps.
First off, try and make sure your car is clean, not because the air flows better but because your’re going to be driving a lot slower and people can admire your ride! The other point is that clogged up muddy wheels and stuff is going to affect your mileage if only very marginally.
Whilst your at it though, look at getting rid of any unused items that will disrupt the air flow and have a look in your trunk and remove that empty crate of beer you’ve been carting around for days now because you keep forgetting to take to where-ever you should be taking it… Okay bad example but still don’t cart any extra baggage around that you aren’t using (like the wife); it’s extra weight.
And on the subject of weight look to only fill your tank to about half for town use and commuting. On long journeys that’s a different matter. Personally I don’t follow this rule because I don’t fill my car up when it needs fuel, rather when I think prices are at there lowest. This sounds bizarre but I’ve noticed here in Germany that on Monday afternoons fuel prices always seem at their lowest.
Right. To driving…
Before you turn that key make sure you’re ready to drive. A stationary car is doing ZERO/mpg – FACT! We all like having the car warm after we’ve finished scraping the ice and clearing the snow but we have heated seats for warming us up quickly.
Incidentally I did start my engine this morning and my fuel usage went from 7.6l/100km to 8.3l/100km in just 2 minutes of me cleaning the car off. If you’re enjoying warmer weather at present, don’t turn the air-con down to ‘LO’, put it on it’s highest setting, i.e 27ºC and gradually lower the temperature to a comfortable level. This will have a lesser effect on the engine and quite often, will stop you feeling like you’re an F1 racing car in a wind-tunnel.
So….. with all that over with, it’s time to concentrate on get the most out of your tank.
A lot of driving tip articles will tell you to use full acceleration to 2,000rpm and change up and do not exceed 60mph/100kmh. What they don’t realise is that some of us have turbos and things work a bit different under the hood.
I recommend you accelerate moderately and if you have a turbo gauge then try to keep the needle at about a 3rd. For classics and NG900/9-3 this will mean no orange or red for you anymore. If you know when your turbo starts to kick in, then change up either before that happens or before 2,000rpm. I usually change up at around 1,700rpm in my Viggen.
If you drive a Diesel then remember you have a turbo too, that’s why you don’t need to book into a hotel when you pop to the shops. Do try not to go over 100km but if you do, keep under 3,000rpm whether running on Diesel or Gasoline – the difference of just 100rpm is quite astounding.
As before, the key point here is that having your car stationary is BAD. I’m not trying to teach you how to suck eggs here, but in the usual mundane commute we get so used to following the car in front we forget to read the road ahead. Keep a bit of distance between you and the car in front and use that space as a buffer. If you see a car ahead waiting to turn, then take your foot off the throttle.
I also almost always use my cruise control. I’m constantly activating it once I’ve reached my required speed, which I set to about 5mph over the limit to compensate for an inaccurate speedo and to try and avoid ticking off other motorists.
Another example: what to do when you reach a motorist that is driving slower than the speed limit? You can over-take, and the small amount of fuel burnt in a short burst of acceleration will be rewarded by the clear road ahead. However, if you know you’re just about to drive into a slower speed zone anyway then ease off. There is no point wasting the fuel only to have to brake again. The most economical way to slow down is to use your car’s gearing, so try to avoid heavy breaking.
Finally, you can try everything to keep a fluid momentum but you are going to reach a point when you will have to stop. Traffic lights, railway crossings, etc., If it looks like you’re going to be stopped for any length of time, turn the engine off and prepare yourself to be ready ‘for the off’ again. Some analysts have reported that a vehicle has to be stationary for approximately a minute to warrant starting the engine again. All I can argue against that is that when I’m stationary and the engine is running I can watch my fuel economy decreasing on the SID. when the engine is turned off, that doesn’t happen. When I restart my engine the mpg on my the SID doesn’t miraculously jump to a lower figure either. Who is right? I’ll leave that up to you.
I used to average about 12l/100km in my Viggen. When I turned off the engine tonight the SID was reading 7.8l/100km. It’s not hard driving economically and even if fuel in the US is something like 0.25c (Euro) a litre at the moment, where would you rather have that money: with the garage or still in your wallet?
Of course you could keep all that extra fuel in your tank for the weekend and have a real fun time on some country roads, because the bottom line is this “A Turbo is a terrible thing to waste”
-
16 responses so far ↓
1 ctm
// Jan 23, 2009 at 9:00 pm
Good write-up.
About the ACC. On my 9-3 there is option to set the outside temperature above which it starts. I can choose between 0 C and 13 C. I have it set a 13 C. The only reason a setting a 0 C would be needed is if there is often extreme moisture in the compartment but I seldom have that, especially since I’m most often alone in my car.
So by having it start at 13 C,it basically never kicks in between October and March here in Sweden and that saves some fuel. Also, driving a short distance a hot summer day (say a few miles) will have the ACC going at full blast without you being able to really enjoy the cold before the trip is over. I usually just turn the whole thing off and maybe opens a window a bit. But then again, avoid short trips. Instead, walk or take the bike to the store and get some exercise. That could in the end be worth os much more than the fuel you save.
I also think the Saab manual says that you should run the engine for about 10 sec before driving away with a cold engine. Having it running longer standing still does not accomplish anything. It will actually take a bit longer for the engine to get warm and (in the winter) provide warm air in the compartment. Just drive away, but drive gentle. If it’s real winter, clear the car from ice and snow before starting the engine.
The biggest single thing is the planing. Plan your driving by being focused on what could happen. That together with the cruise control will also generally set you in a softer more relaxed mood.
2 albert
// Jan 23, 2009 at 9:36 pm
Some good points made in this article.
However, there are two points that I wish to give a reaction to.
1. If you have ACC, do not change the tchosen temperature. The ACC itself will turn the airflow to max heat as long as your chosen temperature has not been (nearly) reached.
2. Engine revs. Things are not in any way different when having a turbo. Less revs means less losses. So you should change always to the highest possible/usable gear. The best efficiency is reached at pushing the loudpedal at 3/4 and then accellerate to a speed where the next gear can be chosen.
In my last car (a 1998 9-3 2.0 lpt) I almost never got beyond 2.000 in the lower gears.
There is one drawback: driving at low engine speed causes more vibrations and leads thus often to premature clutch wear (lateral springs fail).
My current car (an 9-3 1.8t automatic) keeps the revs always below 1.600 and is 5% better than the old manual
3 John
// Jan 23, 2009 at 9:39 pm
Be gentle with the controls: no harsh acceleration or braking.
Think of it like this:
- every time you press the accelerator, you are spending money!
- every time you press the brake, you are spending money!
- press either hard and you are spending money very quickly!
4 Tompa
// Jan 23, 2009 at 10:20 pm
Being a truckdriver I use the technique of looking a long way ahead like WooDz so accurately discribed. I don´t need to break that often for other cars and signals, but instead roll and accellerate gently once I see that the obstruction is cleared.
In a truck this save LOADS of money. That goes for cars to. And if you drive a E85 vehicle….
Tom
5 Danni
// Jan 23, 2009 at 11:03 pm
Good write-up. My only comments are:
- Plan your trips
- read those manufacturers recommendations in the manual (there are very good ones on fuel economy)
- when itching to hit the gas pedal, think of an egg underneath it, and you should see the savings at the gas station
6 Ryan M
// Jan 24, 2009 at 12:28 am
About having a half-tank of gas…
You may be carrying less weight, but you’re also unprepared in case of an emergency. I’ve seen (temporary) runs on gas several times, most recently a few years ago when I was in Seattle during an epic wind storm. Caused a temporary run on gas stations as there was increased demand (from people fueling generators) and decresed supply (from gas stations without fuel).
I’d rather carry a few extra lbs and be ready in case of an emergency like that. In fact I start planning to refuel when I hit half-tank.
7 Ken H
// Jan 24, 2009 at 1:04 am
Some other points:
- On my little manual Peugeot I’ve tried the full accelerator and low revs technique, and according to the real-time car computer the car does use less gas. On full throttle and low revs it will not jump over 10l/100km during acceleration, whereas a light throttle with some more revs will easily give more than 10l/100km during acceleration. Of course then there’s the time factor – is less time on higher consumption as good as more time on less consumption…?
One other ting, pump up the tires.
8 Tim in Denver
// Jan 24, 2009 at 2:00 am
oh man, you’re all kill-joys!
No way!
STEP ON IT! That’s what the turbo is for!
STOMP on that egg, Danni!
9 Rune (the other one)
// Jan 24, 2009 at 8:10 am
Has anyone actually checked that the mileage indicator is accurate? (the mythbuster episode where they compared AC vs driving with windows down seemed to suggest that the mileage indicator is not accurate at all)
I will start checking my odometer whenever I fill up my tank.
10 Richard
// Jan 24, 2009 at 9:19 am
@ Rune – I’ve been keeping tabs of my mileage as I fill up and it does actually translate pretty close to what the SID calculates. Of course my calculation is an average over the last tank of fuel [(litres filled/(km driven/100) to get litres per 100km] as opposed to the continuing averages that the SID calculates.
On a road trip last spring to Vancouver (some 1300km) with a fully loaded car (2002 9-3SE) I was able to squeeze over 900km on a 64 litre tank of gas. And that was running on snow tires while averaging 110-120km/hr. Love how the Saab just eats up those km while sipping the fuel!
However, as others have commented, city driving ain’t quite that pretty. Which is why I tend to leave it in the garage and walk or bicycle if at all possible.
11 PT
// Jan 25, 2009 at 1:22 pm
Thanks Woodz, everyone. Interesting thread. Lets not turn into hypermilers though. My $0.02 worth:
Use the gears instead of the brakes
look ahead to anticipate traffic & road conditions/obstacles
accelerate harder in 2nd gear than in first – ie when you’re rolling
keep your speed through bends and curves rather than braking/accelerating. Learn to pick a line and drive through it.
Keep your tyres inflated (preferably with nitrogen), steering aligned and wheels balanced.
Only drive when you need to.
All of the above are easily done in my experience and I get great mileage + long tyre/brake life.
12 Bruce
// Jan 26, 2009 at 1:47 pm
-A couple of other suggestions:
-Keep the car polished–it feels so good even if it doesn’t help!
-Keep the tires inflated to the recommended pressure
-Change the air filter annually (more often if youd rive in dusty places)–mine is overdue for a swap this week, so the numbers below will improve.
-Avoid gasohol (the 10- to 15% stuff so common in the USA)–much less efficient than 100% gasoline; using less polutes less; E85 is a different matter
- use that cruise control whenever possible, but never on a slippery road
- Drive with a tailwind! (On a run to Toronto and back to Montreal this weekend–about 500km (350 mi), driver plus two passengers and some luggage, temps between freezing and negative 15C, on winter tires, I got about 8l/l100km (about 28 US mpg) into the strong headwind with wet roads and 7.2 (about 32 US mpg) with a light tailwind (and a long stretch with the SID showing 6.8) on dry. This was on a 2.3T 9-5 with three aboard averaging 108 km/hr (9-3s should do better). Consumption runs up around 10 in town, but that’s not bad. I compensate by walking to work.
Unfortunately, in a 9-5 with those 10 generous ws and headlight cleaning jets you need a few spare gallons of -40 solvent in the trunk–used a gallon each way on the road spray.
I once read an article (sorry, cannot recall the source) that compared AC use to open windows on the same vehicle at highway speeds and there was no difference, so be comfortable whichever way you prefer!
13 Kroum
// Jan 26, 2009 at 2:59 pm
Great write-up, WooDz. I guess my abysmal fuel economy can be largely attributed to having too much fun with he X.
No way I am changing gears under 2,500 rpm, and I can’t seem to keep that turbo needle calm for long periods of time.
I’d just throw in a cautionary comment on gearing down vs. breaking. I myself despise drivers who constantly ride their brakes and this is a very, very common nuisance in North America. However, gearing down does wear the clutch as much as braking wears down he pads and rotors. And technically, clutches are more expensive to replace than break pads.
14 AEROPILOT
// Jan 26, 2009 at 5:36 pm
What do you want a Viggen for ?
With your driving style you would be better off in a fuelsawing crap car.
I would hate to see a sporty Saab with engine shut off at traffic lights !
Get ready for take off, and forget about fuel prices when you are pilot in a Viggen.
Anyway best price / performance is achiewed by always using highest possible (98-100) octane fuel, while Trionic is is adjusting power output according to fuel quality and reduces power (5 15%) by low octane fuel !
Driving with your style, your car must be lame, while Trionic have “adaptive learning” and “reads” your driving behavior and sets in for that, meaning your Viggen will not perform it’s best and be “fit for a fight”.
I feel sorry for that car, it deserves better!
Use it for what it’s been made for !
15 SAABoy
// Feb 2, 2009 at 7:07 pm
@ AEROPILOT…
I ‘destroy’ my 9000 aero one day, and get actual 35 mpg (USA) with 92 RON it in the next day. I think many of us enjoy having the flexibility of great mileage and great performance… Otherwise we would drive a ‘theres no replacement for displacement’ car…
16 WooDz
// Jun 25, 2009 at 9:31 pm
Just like to add a comment for AEROPILOT.
The car is ready for a fight as proven a few months ago against two Audi A5’s.
It could be that they weren’t up for a challenge but it didn’t look that way when they entered the Autobahn, and not when they were tail gating me as I was sat behind an over-taking lorry. Although my maximum speed was less than theirs my acceleration was not. By the time they caught me up due to traffic, it was time for me to hit the gas again. Suffice to say over what seems like 50-60Km they never reached the point where I needed to let them past. It’s surprising how steady this car feels at 230km/h