Premium or super unleaded?

[Ovlov]

Good evening. Currently filling my T3 R Design with super unleaded (RON 98) rather than premium (RON95).

Is this a waste of money? Are there any benefits in using higher grade unleaded petrol? Thank you.

[Greggspies]

Can't speak for the T3 but my understanding is that engine management systems adjust parameters according to the fuels calorific value so with a better quality fuel will need to burn less. You should get better fuel consumption but whether it's sufficiently better to offset the increased cost is one you'd have to calculate.

[Felindre]

Volvo specify 95 RON, it's listed inside the fuel flap.

[ciuncky]

95 will work just fine. To see the difference between 95 and 98 you need to run the car at optimal speed (that's about 55mph) for the majority of time which is a bit impossible; Seeing financial reason behind this won't be possible (ie making it cheaper to use 98 in the long-run).

HOWEVER.
Usually 98 gas has other additives added, especially for engine cleaning. I tend to fill up with premium whenever we go on a long trip and put 95 for weekday commuting.
So if your preferred gas station adds something fancy, it might be worth occasionally. I'd recommend Shell Premium but i know some people can be very anal about branded fuel so...to each their own

[m@rk]

All valid comments above and there are many tests online that all seem to agree that you might see a slight improvement in MPG is you are lucky but the cost difference means you don't actually save any money.

But ciuncky makes a good point which mirrors some advice I was once given by a petrochemical scientist who works in R&D for Shell. She suggested that whilst there is little benefit in using premium fuels day to day, running the premium fuel for perhaps one tank in every ten would effectively help clean some of the build ups you get over time due to the increase in detergent in premium fuels especially if you normally use cheap supermarket fuel.

Apparently in the case of Shell, their normal "Fuel Save" petrol and diesel already has a high level of detergent in it so the cleaning benefit between that and the Shells own vPower stuff is less

Short answer

No it's not worth the money but running one tank in ten reps keep your engine running better long term

[Ovlov]

Thank you all for your thoughtful and helpful replies.

[WelshRobin]

For what it's worth, the Volvo handbook says this:
"RON 95 can be used for normal driving
RON 98 is recommended for good power and low fuel consumption"