I've been using the above in my car for a few weeks now and I must say I'm impressed with the performance I've been getting from it.

My car is running very high boost levels, no known mods but it appears that the APC is very "tolerant" and is allowing boost to build to the kind of levels usually only seen on heavily modified cars. A few times I was able to develop massive boost (i.e. a good 5mm past the end of the red) on a fresh tank of Optimax, something that I wouldn't be acheived on BP SUL, which was usually my fuel of choice. However, the Sainsbury's 97 RON is equally impressive, if not better. I find that on a tank of fuel which is a week old (hence the octane has "decayed" slightly) boost will rise to well past the end of the red line.

All this and it's a good 5p cheaper per litre than BP SUL and probably a penny or so cheaper than Optimax.

Ah - interesting finding.

I have always wondered about the powers of super unleaded fuel.

Do you really think it adds more more power than the normal unleaded? http://www.saabscene.com/forum/images/smilies/fawlty.gif

I find that on a tank of fuel which is a week old *[/b]If only I could keep fuel in my tank that long... I fill up every 3 days

Steve

Do you really think it adds more more power than the normal unleaded?[/b]There is a notable difference in my cars performance when it is running on the Sainsbury's 97RON compared to the 95RON fuels. I know on the LH/APC cars Saab recommended 98RON fuel.

Sounds good -

I notice in my 9-3ss handbook it recommends RON97 for the aero 210bhp motor but for the other (less powerful) petrol models it says use RON95.

As a owner of the 1.8T I assume I can do no harm to the engine if I switch to the more potent RON97? http://www.saabscene.com/forum/images/smilies/fawlty.gif

Would these variations in boost occur with a car with a Trionic 7?

I can understand if I get lower boost with lower RON (i.e. to acvoid knocking), but greater?

I always use Optimax, and have done since new.
I notice no variations in max boost - always just touches into the red.

You've got to wonder where Sainsbury get their Superplus from. Shell per chance????

Aero,

remember that the likelihood of knocking is proportional to ambient air temperature. You may find that in the cold(er) months, the management system will run max boost on 95 octane fuel. Wait until we get a roasting hot summer (or drive to Sicily) and try again.

I was thinking the same as Aero. If the Trionic 7 measures torque and adjusts the engine to match a pre-programmed torque curve, any upgrade in fuel will surely be a waste of money.

If the Trionic 7 measures torque and adjusts the engine to match a pre-programmed torque curve, any upgrade in fuel will surely be a waste of money *[/b]Good point that! but I have used optimax for as long as I can remember so can't say if there is any difference in performance,I will continue to use optimax as long as it is sold! This may be a con but I have got into a routine now and my 9-5 seems to like it,I may be a fool for paying over the odds for my petrol?

Originally posted by sgould:
I was thinking the same as Aero. *If the Trionic 7 measures torque and adjusts the engine to match a pre-programmed torque curve, any upgrade in fuel will surely be a waste of money. [/b]In fact, Trionic 5 has a pre-programmed boost curve, so the same applies. You are correct that upgrading fuel is a waste of money, as long as the fuel you are currently using allows the engine to reach the pre-programmed curve without knocking.

As Mark B points out, 95 RON might be enough in cold weather, but in warmer weather, you might find that 97 or 98 is necessary to keep the car performing well. On my 9000, I can see what the boost is doing on the gauge. I understand that the 9-5 boost gauge is rather more complicated and might not give this sort of direct information.

Presumably only limited adjustments can be made before knocking occurs, therefore with lower octane fuels you get lower boost?

Might be talking thro' my a**e 'cos I not sure I fully understand.

Do you know if the standard gauge on the dash of my aero is accurate enough to note any variations ?

I don't see how the engine management system can *measure* torque, without having some very fancy sensors measuring the twisting forces in the crankshaft. I can see that it could have a 'torque map' plotting rpm against throttle position in which the (torque) numbers are merely relative to each other, rather than having any absolute units.

Mike

Originally posted by Mike Bz:
I don't see how the engine management system can *measure* torque, without having some very fancy sensors measuring the twisting forces in the crankshaft. *I can see that it could have a 'torque map' plotting rpm against throttle position in which the (torque) numbers are merely relative to each other, rather than having any absolute units.

Mike [/b]It doesn't measure torque, it only measures boost, fuelling, engine cycles etc and "senses" for knocking. As Bill says;


Trionic 5 has a pre-programmed boost curve, so the same applies. You are correct that upgrading fuel is a waste of money, as long as the fuel you are currently using allows the engine to reach the pre-programmed curve without knocking.[/b]Whereas LH/APC systems simply allows the boost to build up to a safe level, which is below the point at which knocking is "known" to occur.

On the question of where Sainbury's get their fuel from. at the Hamble Hampshire there is a shell/bp fuel depot directly fed from the oil refinery at Fawley,if you stay there long enough you will see tankers from Tesco, Sainsbury, Asda and other well known names. Makes you wonder

Also as a bye 98 ron unleaded is 1 euro in France

Originally posted by Mike Bz:
I don't see how the engine management system can *measure* torque[/b]What Trionic 7 actually does is measure airflow, temperature, boost pressure (actually manifold absolute pressure, since the pressure is often below atmospheric pressure), along with a number of other parameters, and predicts what throttle plate position, boost pressure, fuelling, ignition timing, etc. will produce the engine torque output that the accelerator pedal sensor indicates is appropriate (taking into account also any tendency towards wheelspin sensed by examining the wheel sensors, to incorporate a traction control function on some models).

Therefore, T7 does not follow a pre-programmed boost curve, but a pre-programmed torque response, so anything which makes it safe to use a higher boost pressure will not necessarily result in an increase in torque if this exceeds what the system "wants" to supply.

Gelcoat,

oil companies do not waste money shipping fuel about the country (we'd end up paying if they did!). So if you live in Hampshire, your petrol will come from Esso's Fawley refinery. If you live in the north west, it's from Shell's Ellesmere Port facility, adn so on. The main difference between the brands is the additive package, which can be added in the road tanker, rather than the refinery product. I'm not sure how the unique products, such as Optimax and the Ultra Low Sulphur products fit into this, but for the standard, mass market products it's certainly the case.

Just to add my 4p/litre.

My 9000 AERO definately runs better on Optimax rather than normal unleaded.

If i'm running low on Optimax I'd go for super.

However in my wifes 9000 LPT CSE Optimax/Super seems to make no difference at all.

That proves it then ????

What I really want to know is - Why is petrol most expensive on motorway services ?? , when surely it should be the cheapest.

I feel a rant comming on.

I'll have to look into what the manuals do... but on the auto 9-5's torque is measured by the gearbox alledgedly...
in fact using tech2 you can see the torque value, whether this is actual torque or requested torque, I'll have to let you know!

Also helps, as the auto use a diff protection system, when wheelspin is detected, the DPS via the auto ecu request trionic to lower the torque to reduce wheelspin and save the diff!

Motorway petrol - only bought by people who don't pay for it themselves.

Best petrol scam was a few years ago in the days of Green Shield Stamps and free gifts (and £1.50/gall!!). Petrol price on street sign £1.50. Petrol price on pump £1.75. On paying you we asked if you wanted the 25p discount or vouchers to that value for use in their shop. All company car drivers took the vouchers and a receipt which only stated the price, not the quantity http://www.saabscene.com/forum/images/smilies/eek.gif

What I really want to know is - Why is petrol most expensive on motorway services ?? , when surely it should be the cheapest. *[/b]During the campaign the other year for cheaper petrol I was driving along the M3 and needed some fuel .. so I pulled into the services and put just enough to get me to where I was going, mainly becuase they were 10p per litre more than the A road garages. When I went in to pay they asked if I wanted to sign their campaign for cheaper petrol!!.

They got a few choice words

Steve

Look at my maybe a silly question thread in Saab Turbo team europe forum http://www.saabscene.com/forum/images/smilies/rolleyes.gif

Alyn

At least in Norfolk it's usually reasonably cheap (well as cheap as stafford,and stoke).

Price has just gone up to 74.9 for unleaded (that's up 4p in 6 weeks). Super and Optimax are about 77.9-79.9p

Andrew

Well! There you go; it's 78.9 for unleaded in Basingstoke and we're a lot nearer to Fawley than you are Mind you, I went to fill up yesterday and Optimax was only one penny
( or 'one pence'as most shop assistance say; 'there you go, one pence change, fanks' )more at 79.9 so I opted for that.

I have just started using optimax in my Abbott 9000 CSE and it definately feels smoother. Didnt know Sainsburys did a similar version. Optimax does make a big difference as my TVR chokes on anything less. It is recommended by TVRCC to run your TVR on optimax. Mark http://www.saabscene.com/forum/images/smilies/rolleyes.gif

Welcome to Saabscene Scoobysnax

I find that Sainsbury Super Plus, is not the same as Optimax, it just doesn't feel as smooth

Also, on my way back from Belgium last year, filled up with BP Super Plus in France, and it seemed to give a better performance than BP Super in UK.

Cheers, Vince

I'm also a great fan of Sainsbury's super u/l and find it gives me 9000 Aero a bit more go when compared to Optimax, even though Optimax is supposed to be a 98 octane fuel. These fuels have no noticeable effect on me gf's 9-3 2.0T by the way.

Sainsbury's is also the cheapest, especially when you take into account those nice money off vouchers...sorry Shell. Currently paying 79.9p in Leamington - which falls to 75.9p if I over spend on sticky buns!

I've heard it said that a T5 will lose 25 bhp if you use u/l rather than super...but it is a Volvo after all.

Forced to fill with ordinary unleaded yesterday.

Feels as flat as a very flat thing now.

When I fill up with the propper stuff do I need to do anything? Or will it sort its self out?

Alyn

Alyn, the car should adapt. For Trionic cars follow the guidelines on Saab9000.com (http://www.saab9000.com/procedures/powertrain/adaptation.html), I believe thsi adaption technique works with most trionic cars.

Chances are that it will adapt back to Super quite quickly on its own anyway, without having to do anything special, especially if you've only run one tankfull through. Then again, I like to do the occasional adaptation run anyway, just to maintain maximum performance.

i use optimax in my 2.0lpt 9-5 and find it not only smoother (and slightly quicker) but also better mpg is acheived after the 2nd/3rd tankfull than on regular u/l

In Hong Kong, RON98 unleaded costs the equivalent of £0.84 per litre (those fancy Mobil Synergy and Shell Vortex cost even more). The cost is one of the highest in the world but it doesn't really hurt because the journeys are very short by European standard.

I'm shocked that petrol costs so much in the UK, bearing in mind that the UK is an oil producing nation and British motorists need to drive for distances far longer than us on average.

So are we ngu, so are we!!

Petrol in the UK is very cheap. It's the tax that the government puts on it that makes it expensive to buy