95 or 98 petrol - what do you use?

[k4rma]

Bought a new 132 TSI Tiguan. Obviously 95 is the min but wondering if many people opt for 98 instead? Is it worth the price differential? Make much difference to the engine?

[zzc2010]

Are you kidding? Always 98!

[OZROD]

Here are a few youtube videos on this subject.
In this one, they seem to be saying that the move from 95 to 98 makes about 4% difference in pressure (98 allows higher) because the cylinders can advance timing further on 98.
YouTube

In this one seems to show between 1 and 4 additional BHP over standard fuel.
YouTube

Hmmm.

[mickofoz]

Are you kidding? Always 98!

I used to believe more is better and used BP Ultimate exclusively. However, it made no difference in fuel economy and no difference in performance. Yes, BP claim it keeps your engine cleaner but according to the VW service center, there were no visual difference in oil colour and spark plug wear. But as with most premium products, if you want to believe something, you will always argue against other opinions.

[CWolf1]

Costco fuel (red).

[Umai Naa!!]

I'd be more concerned about detonation than fuel consumption and performance.

[Ozsko]

Are you kidding? Always 98!

Why? Lower octane burns faster.

[zzc2010]

Why? Lower octane burns faster.

Purer the better


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[Ozsko]

Give me some hard facts and I might agree.

[tigger73]

You can run into issues of pinging/detonation if you run a lower octane fuel in an engine that is tuned for a higher octane. Particularly at higher ambient temps and higher loads.

On an ongoing basis this can do permanent damage to the engine internals requiring expensive repairs.

Your car is designed to run on 98 fuel so you’re well advised to use it. The sticker on your fuel flap has a large 98 and small 95 meaning you can use a bit of 95 in an emergency but it’s designed to run on 98.

For the cost of a couple of $ a tank it’s not worth the risk of doing damage to your engine.


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[theresanothersteve]

Make yourself a spreadsheet. Run a few tanks of 95, recording how far you went and how much you used. Then run a few tanks of 98, doing the same. You can then compare the results.

I did that with a Holden V8 (2 actually) and found it preferred Shell 98.

Started with the Shell in the Jetta, but found it preferred Vortex 95.

Thew way I see it is the fuel that provides the best economy over an extended period has to be burning efficiently.

BTW, both the Holden and VW dealers were adamant I stay away from cheap fuel chains and stick to Shell/ Caltex/ BP. (We don't have Mobil in SA anymore)

[doc_777]

95 is the standard fuel in Europe. On a 132TSI engine, 95 is the required fuel - anything higher than that is optional.

[Ozsko]

The computer and anti knock systems will pull timing out to prevent detonation, that is what they are there for. The latest Tiguan does not specify 98 at all on the fuel cap, the only specification is a minimum of 95, I just went and had a look at mine to confirm that.

[k4rma]

The computer and anti knock systems will pull timing out to prevent detonation, that is what they are there for. The latest Tiguan does not specify 98 at all on the fuel cap, the only specification is a minimum of 95, I just went and had a look at mine to confirm that.

Yeah that suggests to me the engine is tuned for 95 and using 98 is unnecessary.

[DR074]

Make yourself a spreadsheet. Run a few tanks of 95, recording how far you went and how much you used. Then run a few tanks of 98, doing the same. You can then compare the results.

I did that with a Holden V8 (2 actually) and found it preferred Shell 98.

Started with the Shell in the Jetta, but found it preferred Vortex 95.

Thew way I see it is the fuel that provides the best economy over an extended period has to be burning efficiently.

BTW, both the Holden and VW dealers were adamant I stay away from cheap fuel chains and stick to Shell/ Caltex/ BP. (We don't have Mobil in SA anymore)

Better yet

Fuelly - Track and Compare your MPG

Looks like you can compare your car to other cars of the same type