I got an email in from Renee the other day. She wanted to tap my technical expertise.
Seeing I have no technical expertise, I thought I’d post the question here and let you lot get in on the act. Renee’s question is a two-parter, as follows:
I love my used Saab 9-3t convertible 2004, which I bought about six months ago. I wondered if you could help me with a techie question?
Ever since I bought the car it has had a problem with randomly revviing up as I am driving. Do you have any idea what could be causing this and how I can get it fixed if it is random?
Secondly, what brand gas is best? I was using Chevron premium but have switched to their regular due to cost. However, I hate to support mid east gas when I could buy American…any suggestions?
Firstly, congratulations on your wise choice in picking up an irrestivertible. A fine drive in anyone’s terms. I suggest getting a BSR upgrade for some enhanced zippiness. It’ll really bring it to life. Our email circle here in Australia have been discussing the BSR unit over the last few days and one guy who’s done the modification to his 1.8t SportCombi absolutely loves it.
Of course, that’s got nothing to do with your questions, but I thought I’d offer it up anyway.
On the first issue, I’ll have to defer to those that tune in here and actually know what they’re on about. Something electrical, perhaps?
On the second issue, I have to confess that I’m an absolute believer in the marketing of the oil companies. I only use premium. BP Ultimate, actually. I don’t know if it’s just phychological, but my cars definitely do feel like they’re running better, and are more responsive, on the premium juice.
Standard fuel here in Australia is 91 Octane, though I think we use a slightly different measuring system to the US. The BP Ultimate stuff is 98 octane, so it’s certainly supposed to have some more zip than the normal stuff.
I think it’s even more important to use the good stuff if your car is modified and the new tuning is based on an expectation for good fuel.
In terms of the origin of the oil – stuff it. Everyone you’re buying it from is way wealthier than you, so you’re lining someone’s pockets either way. Just whose pockets they are is almost impossible to tell at any given filling station. The only way you could be sure is to buy a diesel and start making your own.
——
They’re just my token thoughts. Over to the rest of you.
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The countries have different naming conventions of the gas. Even the name “gas” is weird for us in Hungary, because the gas means here the really gaseous susbstance, I mean if you ask for gas in Hungary everybody will think that you need a oxygen or metane or similar.
Here we call the fuel “benzin”. 
The Premium fuels I used only a few times, because they are 10-15% more expensive, and can’t add 15% more power. 
We use mainly 3 RON type: 95 is the standard, some brands have 98 and the premium is 100.
Actually, the Trionic can adopt for the better fuel and if you have any upgrade for the ECU software, itt will perform better with the higher octane fuel.
The Viggen’s manual recommends 98, I use it mostly, sometimes the higher (100).
But I know that the same RON paremeter has different name (different numbering) in other countries.
Brands: here in Hungary we have major brands as Shell, OMV (Austrian), Esso, Agip, Jet, MOL (Hungarian), Castrol. Most of them buy the gasoline/petrol from the same source: the wholesale of hungarian MOL then add some additives and Shell’s V-Power Racing premium fuel also comes from other source.
I found that the there are no major differeces between 98 fuel from different brands, due to their source is the same, only the additives are different.
Sorry, I forgot: OMV also supplies their stations from its own wholesale source, not from MOL, as far as I know…
People have many different opinion, however most of the agreed that some brands have better some have worse fuel… but the preferences are various.
if you live near Canada you could always come up here to fill up. Gas is down to $1.20 (ok, that’s for a litre). The good thing from your economic nationalism, however, is that we’re a net exporter of oil, and seeing as how our oil industry is mostly American owned, that means that most of those ridiculous oil profits of late end up in the hands of US shareholders.
If you’re not close to Canada, isn’t Citgo Venezuelan? That would gove your money to a third world country engaging on a radical social experiment. So, it’s your choice.
evo Magazine had a full-line test some time back (I think 2007) of the different petrol (gas) available in the UK and they used a VW Golf V GTI as the guinea pig. The higher octane fuel is preferred in most high revving high performance engines (some stating in the owners manuals that 98 RON is preferred, though some vehicles can dip as far below as 91 RON with the resultant loss in peak power – the car producing less power at its peak due to the lower octane rating). I have seen test results performed in a BMW M3 MY05 and a Mercedes Benz C55 AMG MY05 at sea level producing better peak power ratings and better fuel economy on minimum 98 RON, not the muck distributed currently in the form of 93 RON or LRP (lead replacement petrol) or the regular 95 RON. The downside is that the higher octane fuel is on the expensive side.
I’m wondering if Renee’s 9-3 is an automatic or a standard, and if the revving occurs while the car is in gear and in motion? I won’t pretend I’m qualified to answer the question, but it sounds like a transmission or clutch issue if the engine’s revving up while in gear. Thoughts anyone?
Here in the UK, we have learend that if you fuel your modern car with cheap fuel from the supermarket or cost cutter garage, the car will run rough, have less performance and crucially, will exhibit signs of carbonisation in the cyclinder head- something that went out 40 years ago with cars that regulrly needed a ‘decoke’.
So, it seems the marketing hype of premium branded fuel is correct. The answer is this- expensive brand fuel is of a superior ‘cut’ of fuel and contains cleaners and additives which will wash the fuelinjectors and cyclinder bore lienrs as well as keeping the valves clean.
Cheap supermarket type fuel- MAY not contain such additives and it has been demonstrated by consumer bodies, that the valves on cars fuelled solely with cheap fuel, clog up very quickly.
Of course a Saab should be able to adapt on its own to different octane (RON) ratings. BUT, if the fuel is heavy, sulphurous and minus the cleaning agent additives, the car’s combustion cycle will not be as it should and the bore liners may well suffer premature wear- BMW had this problem a few years ago- made worse in the Uk by our cheap and dirty fuels.
Never use cheap fuel or, never use it for a long period, always flush thru with a tank of the BP or Shell special stuff once every four or five fill ups.
All i know is that my 9-5 loves Shell Ultimate and hates supermarket fuel- indeed I recoup the extra cost of the petrol thru increased mpg- about 2mpgallon.
Hope that helps.
My OG 9-3′s recommended fuel is 95 RON. I find it to be somewhat sluggish on 91 octane.
I usually use 94 octane E10 ethanol blend which it’s quite happy with and it’s fairly widely available in Australia. Every so often I top it up with some 98 RON E10 or BP Ultimate. The octane rating system is different in the US, but use what’s recommended in your handbook or on a sticker near your fuel cap or the next higher rating and you will have no problems.
As to the revving problem, try some injector cleaner first and if that doesn’t work contact a Saab mechanic.
I find that I get about 10% better fuel economy filling-up with the highest available octane (Sunoco Ultra 94 here in Canada) relative to standard gas. Given that the price difference is roughly 10% as well, I get the extra power for free. Last time I drove in the US, the math was roughly the same.
Intermittent problems are hard to diagnose. Assuming that the problem occurs at idle, the culprit would have been your idle air control (IAC) valve on a NG900/9-3 hatch (pre-2003). The fix is either cleaning or replacement.
I am not sure what strategy the post 2003 cars use for idle control. You may want to check the car for “pending codes,” which are engine codes that are not serious enough to trigger a “check engine” light. Almost any mechanic should have the tool to do this (I believe some auto parts stores will do this for free as well).
You could also see a mechanic that is familiar with Saabs. There may be a technical service bulletin (TSB) for this.
The other option is to wait until it gets worse, in which case it should be easier to diagnose.
Try Hess, Marathon, or Sinclair. These tend to be regional so you probably wont find all three where you live. Sunoco is probably coast and probably a high Canadian oil content in their fuel.
Personally I consistently get better milage with Hess fuel in a variety of vehicles. I suspect their fuels may have less ethanol.
Your supposed to run premium grade fuel in your car and if your T-7 is anything like my T-5 2.0t you will notice a loss of performance using 89 octane fuel. However I notice that I get better tank to tank milage using the mid grade which makes me think that the trionic is lowering boost, less power, but ignition retardation, to combat detonation, is not so much that fuel economy suffers.
The US top tier fuels; BP, CHEVRON, EXXON, and SHELL have 93 octane fuels with detergent that claim to keep your engine cleaner. By this they must mean the combustion chamber and valves. I don’t doubt these claims but I suspect that Americans, in general, could do more to combat carbonization by letting their motors run at higher speed. If your not in the habit of running your engine higher RPM I suggest the occasional “Italian Tune-up”
I’ve become a big believer in only using gas listed on toptiergas. I’d suggest reading up on it and clicking their Retailers link. The chief thing is that only these retailers have enough detergents in all grades to keep an engine from forming deposits. By the way, Chevron is on that list, a good choice. I, however, in my 2.0T, us Shell V-Power 93 octane which Shell says has 5 times the govt required level of detergents, enough to clean an engine that already has deposits. By the way, BP is not on that list, despite their silly ads.
My experience with V-Power, when I started driving my 04 Arc in April 07, the car was fine, but would sputter occasionally during warm-up. In my daily driving, trying various brands except Shell, I never got over 27 mpg. I found toptiergas, and found Shell was the only retailer in my area that was on the list. I’ve stuck with V-power, and the sputtering has completely disappeared, and the mpg gradually increased until now where I’m pushing 30 mpg, oftentimes well over, and I’m definitely a “spirited” driver.
I know talking gasoline is like talking politics or religion, but that’s my two cents (or more).
I use E85, of course.
I use E85 too…
And moreover my Saab is more powerful!!!!!!
Mine is 100% Swiss, originating from Swiss wood waste, coming from Swiss forests…
So that there is no problem like: “Because of you, people of the 3rd world are starving…”
–> there is NO COMPETITION with food…
Sunoco Ultra 94, blended with 10% ethanol. That is the highest octane number gas available in North America, and my Saabs just love sipping that. Performance and economy both noticably improve.
How does Costco gas compare?
Actually, I don’t really believe even a word of the oil companies.
Mostly what they say about their special additives is in the fuel is a marketing bullshit.
Maybe I will try E85 soon, but I need an ECU software upgrade for it.
Such an interesting topic actually ..
I live in Saudi Arabia .. Okay the fuel here is cheaper than water .. but it because you cannot move from A to B without a car, as there isn’t any neat public transportation.. Dont be amazed when I tell you that the highest fuel grade is 95.. lowest is 91.. officially it is unleaded .. otherwise the refinery on the west coast is old and is still running about 20 years after the real expected lifetime.. and I’ve had an engine & catalyst failure due to lead getting stuch in the catalyst causing back pressure to the engine.. and lots of lead stuck around the valves ..
I’ve had tried the 95 around the Gulf Countries other than Saudi Arabia .. as well as 97,98 & 99 which was expensive ofcourse .. but the car turns out to run much smoother and having more boost not needing to downshift to a lower gear ..
But the thing I’ve been doing for the Past 3 years is using Toulene as an additive AKA Paint Thinner.. I blend about 20-30% thinner and the rest just the regular 95 Octane .. kind of a trick that is safe to the engine.. and raises your octane number.. P.S. Octane boosters doesn’t do much difference but also isn’t really safe for the Catalytic converter.. as it usually contains oxygenated fuels, nitromethane, leaded substances as well..
Just my 2 Halalas
I never ever ever use BP gas. Every time I do, my car (both my old Saab and my Thunderbird) acts funny.
I use Exxon premium, which is 93 AON. If they sold higher-octane gas around me, I’d buy it. Sometimes I use Shell V-Power. I’d use it more often if there were a Shell closer to my house.
Here are a few things I’ve learned:
-Never put cheap gas in finnicky European cars
-NEVER put cheap gas in cars with forced-induction engines
-Cheap gas really hurts both gas mileage and performance
So, Renee, you should definitely not use regular to save money, because it will definitely just end up costing you money in the long run.
Renee,
I’m no gearhead myself, so I can’t help much with the mechanical problem. Take it to a good local indie Saab mechanic, and it’ll keep your costs down. As for the gas issue, I’ve always been a bit skeptical about particular brands of gasoline. However:
Not long ago, my wife filled up our 2002 9-5 Arc with cheaper gas (Sinclair) and discovered the gas gauge and SID were still stuck at empty and wouldn’t move. I asked my local Saab indie mechanic what the problem might be. He recommended using Chevron gas with its Techron detergent, saying the cheaper stuff actually gums up various parts. He said, “I wouldn’t even put Sinclair gas in my lawnmower.”
I was skeptical, but since using Chevron regularly and not just intermittently, the problem has gone away and the car has indeed run better. And one other thing regarding octane: if you live in a mountainous area or will be changing elevations on a road trip, fill up with premium. As has been explained to me, the engine management system (usually Trionic with most Saabs) will retard the engine’s performance to avoid knocking and pinging, but it can only retard the engine so far. If you’re putting a heavy workload on the car (i.e. weighted down and/or climbing hills) you’ll need the engine to work freely as designed. We have to watch out for this problem locally, as those Rocky Mountains can have some pretty tough grades to climb.
Well, as I have yet to put a single drop of gas in my car I am gonna have to say when the time comes it will be something with a 91/92 octane rating. Shell V-Power or Chevron Supreme 92 seems the best idea. I am going to actively avoid any gas that has ethanol until the government deems it necessary that gas is going to have the stuff in it anyway.
I do have a question though am I going to notice any improvement in fuel efficiency if I were to use the 94 octane that Chveron sells here in Canada or am I wasting my money?
Kroum, dont the Turbo X’s use jet fuel?
First of all, octane ratings only tell you what the fuels pre-detonation resistance is. It has nothing to do with energy density. That being said, modern Saab cars can detect pre-detonation (pinging) and retard the timing and reduce boost. Also, boost can be increased with high-octane gas because pre-detonation does not happen until higher boost pressures. It’s possible to have bad gas that has a high octane rating because dirt, detergents and other proprietary additives are not related to octane.
Sport Mode,
It’s pretty typical to not find high-octane gas in mountainous regions for good reason. At 5000′ elevation, atmospheric pressure is about 12 psi, while it’s about 14 at sea level. So, with a 15% reduction in ambient pressure, pre-detonation is not as common. That’s why you see 85 octane gas in the high country. That’s also why cars seem to loose some power in the mountains. The cool thing about Saabs is that they allow you to take advantage of the fuel and ambient conditions with their sophisticated engine management systems. Additionally, you can’t wreck your Saab engine with low-octane gas, it’s just not as powerful.
Have you ever driven your turbo Saab on a COLD winter day. That cold air coming across the intercooler cools the intake air and lets the computer raise the boost pressure, because that intake air is more dense than it would be on a hot summer day.
Most people think that an occasional tank of premium is good for their car. Not true. Regular tanks of high quality gas are most important. (Top Tier Gas was mentioned earlier and is a good resource.) Very few cars can actually take advantage of the difference between low and high-octane fuels. Saabs are one of the few brands that can do that.
All that being said, I prefer to use Premium Chevron gas when I can in my 9000 Aero (5 spd).
~P
P.S. The 300 HP 9-5 biopower monster can make that kind of power because E85 or even E100 has a VERY high octane rating. This allows the turbo to make much higher boost without pre-detonation. This allows the engine to run in a more thermodynamically efficient range of operation, thereby extracting more useful energy from the fuel.
(If I’ve mis-stated any technical aspect of this, please correct me. I wanted it to be readable by everyone, while still being technically correct.)
This paragraph from the Wikipedia explains the difference in Octane ratings in the US/Canada compared to the rest of the world:
It should be noted that this higher rating seen in Europe is an artifact of a different underlying measuring procedure. In most countries (including all of Europe and Australia) the “headline” octane that would be shown on the pump is the RON, but in the United States, Canada and some other countries the headline number is the average of the RON and the MON, sometimes called the Anti-Knock Index (AKI), Road Octane Number (RdON), Pump Octane Number (PON), or (R+M)/2. Because of the 8 to 10 point difference noted above, this means that the octane in the United States will be about 4 to 5 points lower than the same fuel elsewhere: 87 octane fuel, the “regular” gasoline in the US and Canada, would be 91-92 in Europe. However most European pumps deliver 95 (RON) as “regular”, equivalent to 90-91 US (R+M)/2, and deliver 98 (RON), 99 or 100 (RON) labeled as Super Unleaded.
Hence our regular unleaded in Australia (91 Octane) is the same as 87 Octane in the US.
I guess saying I use 87 won’t go over well seeing all these posts about top-end gas.
Costco isn’t bad, either. I get better MPG with them over Mobil.
I run exclusively BP 98Ron (Australia), see Markac’s post above.
I use 93 here in the US..basically the most expensive stuff. But I love my car so it feels good to take one for her
I’d love to see a poll on tires too. What tires do people use on their 9-3′s, especially run-flats? That would be great to hear about. I guess run-flates are intersting to me because I have a turbo-x with that funky pump thing that I know will fail me on a cold rainy night on the side of a road in the middle of nowhere.
beren
joemama – but there’s the thing where they only let you buy gas in 50-gallon drums :p
Well, I’ll put it this way: anyone here who uses cheap gas, try premium and see if it makes a noticable difference in performance, and also see if it helps mileage. I’d bet my entire savings account that it will make a difference with at least one of those things.
note – I have 12 dollars in my savings account and I won’t really give it to you.
I usually go to the Shell station that is right next to my apartment complex. Neither of my cars has a turbo, so I usually just get regular 87 octane.
I haven’t noticed the cars running any better or worse between brands.
In Switzerland, the fuels available are:
Unleaded 95 RON
Unleaded 98 RON
Unleaded 100 RON
E85
Diesel….
All of them, VERY CLEAN…
there is NO fuel below 95… and i am amazed that in other countries you can find 87 RON (?!)..
We have three items to discuss here.
The first one is the technical problem of unwanted high revving. Go to a mechanic that knows about Saab. period.
The second one is the queation of required octane number. A Saab, built after the end of the eighties is designed for use of RON 95 (so that would be ~91 in the USA/CAN). A higher octane number does not give you any advantage! A lower octane number will, under certain circumstances, couse knocking or pinging. Luckily our Saabs detect this and take several measures (lower boost, later ignition, etc.) to end knocking.
The third question is about the petrol quality. Important here is especially the quality of the detergent I think the reactions above (saabyurk) should give enough information on this.
So the right gas is a 91 from a quality supplier (ans as I am living in NLD, I of course think then of Shell).
Albert – “A Saab, built after the end of the eighties is designed for use of RON 95 (so that would be ~91 in the USA/CAN). A higher octane number does not give you any advantage!”
My MY01 9-5 Aero manual says the minimum is 91 RON (Namibia). As to your second statement, I could not disagree with you more. I have driven my 9-5 Aero manual with a full load of gasoline (95 RON) at a cruise-controlled speed of 130kph and got 708km to the tank before I had to fill up on a single drive. Before you ask, we have huge and vast distances to cover in Namibia on well-groomed tarred roads). A week later, I travelled the same distance again and then gassed up with 102.6 RON (called racing fuel in this part of the world – it is actually leaded petrol) and not only did my vehicle performance improve (perhaps subjective), but I covered 820km on a tank on a single drive before filling up again. The exhaust pipe was covered in an ash color (proving that this is leaded petrol with a high octane rating). Please explain what was going inside the engine and the tank.
Gio: 87 octane would be equivalent to 91 octane in Europe. 91 octane is (unfortunately) the standard unleaded in Australia. The other grades are 95 and 98. There is nothing higher here unless an octane booster additive is mixed with the fuel.
@Danni, I do not doubt your findings, but such a measurement is not accurately enough to make statement. Your car is designed for use og RON 95 and will not use the eventual advantages a higher RON could have. If you want to use the extra RON, tou need reprogramming of the engine software. You could use the services of Hirsch, BSR or Maptun. For instance, Hirsch pushes the standard B207E engine from 150/175 hp to 195/200hp, but only when RON 98 is being used.
The fact that a “racing fuel” like you describe gives you more distance could very well be caused by a higher density and/or a higher combustion rate.
@zippy: dont the Turbo X’s use jet fuel? Well, they could if the Turbo X would be equipped with a diesel engine! be sure to use a friction improver when using kerosine though.
Trionic engine management will allow for lower grade gasoline than recommended to be used.There will be an offsetting lowering of performance on average of app.10%.
Danni: PLEASE CHECK. I hope you didn’t really mean “leaded petrol”, but instead meant “leaded substitute petrol”, Lead destroys catalytic converters. Read the comment by Abdullah Al-Ghamdi above. (Unless, of course, South African cars don’t have catalytic converters).
I use mid grade (I think it’s 89), in the ’92 900 and the high octane(91?) in my 9-5, since it has the saab ECM upgrade chip. The local saab dealer(‘saab exchange’) also suggested that I use Shell, since it was among some gasolines tested by GM and on the recommended list. It seems that with all the ethanol crap being used these days there are gasooline related problems with all kinds of motors, even the lawn mowers(they told me to add some ‘gas stabil’) to my lawn mower. I did and problem solved. Adios amigos.
filling up with 93 octane currently.
e85 is a scam here in the U.S. while i absolutely love the idea of biofuels, producing ethanol from corn includes extensive use of fossil fuels to produce said corn and only drives up corn/food prices.
switchgrass is a better option and appears promising, but it seems producing enough to drive the nation’s cars cannot be accomplished without turning the entire nation into a prairie.
we have been spoiled by millions of years of sun energy concentrating energy into fossil fuels.
/steps down from soapbox.
Regular grades (87 in US + Canada, 91 elsewhere) work fine in 9-5s. The SAAB US website finally has this right with regular as the recommended grade. The manual says 87 to 93. I tried a tank of super and noticed no benefit, so prefer to save the money. Driving in the US my consumption is higher becaus of the typical 10% ethanol–effectively wiping out the benefit for emissions because the car drinks more of it. 9-3s need super(93, 97 or 98 elsewhere). The next 9-5s likely will as well. Using higher octane than needed seems like a waster of money. It is also environmentally damaging because of the emissions involved in the refining process. I have only once had a problem with “bad gas”–the lesson was to buy gas only from busy stations with frequent refills that prevent moisture accumulating in the fuel.
B
Thanks so much to all of you for your thoughtful comments. I have never participated in this before. LOL
So again thanks!!!!
As far as my car engine problem is concerned….it is revving up the rpms when I am actually in gear and accelerating. That doesn’t mean fast…this happens easily when I am going along from 20 to 25!
Please advise. I need to know what to do since it is random.
I was wondering about the best gas for Saab in America and thinking of the emails I have received about S. Am. and mid east’s negativity towards us…not wanting to help them with that.
Where I live, it is now mandated that almost all fuels are to contain 10% ethanol. I’m in the Midwestern United States, which is a large corn-growing region. But ethanol as a motor fuel is not very good. In my state (Minnesota), there are a few dealers which sell regular gasoline, that is, without added ethanol. The Minnesota Street Rod Association lobbied the government to allow a few dealers to sell this fuel. This is referred to as “non-oxygenated” or “non-oxy” fuel. They were allowed to do so as long as the fuel was intended to be sold only for “collector cars, street rods, small power equipment” and other special needs. However, there is nothing stopping you from buying this stuff for a regular car. All that they have to do is display a notice on the pump at the gas station. Luckily, there is a Shell station just down the road from me which sells the stuff.
I have found my performance to noticeably increase and my fuel economy to go way up, on the order of a few miles per gallon! It costs a bit more, but with this era of high fuel prices, what is a few more cents going to hurt? In the end, with the increased fuel economy, it probably evens out or even is more cost-effective.