XC40 Premium or Regular Petrol?
 

The emerging picture with my XC40 T3 is that mpg is slightly better than my previous XC60 D3 (although you have to look closely to notice). Now Volvo recommend that you use Premium Grade petrol to get the best from the engine. This however is more expensive than Diesel, so in money terms the XC40 is costing me more to run than the XC60. The obvious question is why not use regular petrol which would turn in a noticeable saving (unless it dramatically reduced mpg)? Any thoughts on the matter would be much appreciated.

I would stick to Premium grade fuel, that is what Volvo recommend and is better for your engine.

I always use Shell V Power but I tend to keep my cars longer than three years and in my opinion my choice of fuel is better for my engine.

You'll have posts from the "it makes no difference brigade" who maintain it all comes from the same tank, but this is not true.

Also in my mind to pay 30K for a new car and run it on cheap fuel does not make sense.

Iain

Yes, that is also my position. Why risk compromising the car by running on cheap fuel or using cheap servicing. I just wondered if there were any views on using the cheap fuel or even mixing regular and premium, but perhaps that is getting too complicated. It does raise the question however of what people do in countries where premium petrol is difficult/impossible to obtain. As a visitor you could just use the regular petrol as a temporary measure, but if you are resident it is a different matter.

So do 'Volvo recommend that you use Premium Grade petrol to get the best from the engine' in the owner's manual?

I'm genuinely surprised that they sell a car that actually needs premium fuel.

Yes -
• RON 95 can be used for normal driving.
• RON 98 is recommended for optimum performance
and minimum fuel consumption

While it says that regular can be used, it is quite definite that premium is recommended for stated reasons. Whether that means the car "needs" premium is an interesting discussion point.

I do wonder why "optimum performance" and "minimum fuel consumption" are considered not normal driving. I guess we really need quantitative comparisons including on the well-being of the engine.

Ever since I owned my first motorbike/car I have only ever used normal/supermarket fuel. I have never had any adverse effect on any of the vehicles I've owned.

Show me some evidence that there is a significant difference between premium and normal fuels and I might reconsider my position. The things I've read about this subject have showed either no effect or a very small increase in fuel efficiency, but not enough to justify the premium price.

If Volvo, or any other manufacturer for that matter, are making cars that don't run properly on standard fuel they should be treated in the same way VW were treated for cheating emissions testing.

I've always used supermarkets fuels in on all my cars in the past. I have had a mechanic tell me that a few times he has found engines with algae growth in the head due to the owners always using supermarket fuel.... Not sure if true or not, again seen no real evidence myself.

However, since buying my XC70 at the start of the year with 40,000 miles on it, (I am sure the previous owner would have been a supermarket fuel type user), I have been more inclined to use Shell of BP fuel stations for Diesel. Now the cost difference isn't really that much. Ie shell/BP is maybe 1 - 3p more per litre than say tesco. A full tank, maybe a couple of £s difference. I plan to keep this car a while to putting in a better grade of fuel, that I do know. I do put in redex or wilsons oil diesel treatment to keep things clean. Maybe once every couple of months I'll go for Shell V-Power.

At the end of the day it's a personal choice, but Volvo will have established what is the optimum fuel for their vehicles. If you do a lot of miles every week then it may not be cost effective. If a tank can last a couple of weeks with small shuttle runs, then maybe not so bad. For me I have moved away from supermarket fuels unless I need to use them, for the sake of engine longevity (so I think), but would be good to find an actual study on this.

Still there's speculation....

https://www.simplemotoring.co.uk/sup...branded-fuels/

There is no question that higher octane fuel will result in improved mpg and performance. What matters to most people though is not mpg but £/mile. So the question most people want to know the answer to is whether the improved mpg is worth paying the extra for. I suspect not.

Note that Volvo here are referring only to octane rating. They make no mention of premium fuels in terms of additives such as the improved cleaning power and friction reduction that e.g. Shell V-Power claims to have. This is something separate, although the two are often conflated as fuel companies have decided to put their premium marketed additives only in the high RON fuels due to the limited number of tanks and pumps in petrol stations.

OK, things are becoming clearer. RON 98 petrol and premium petrol are not necessarily the same thing. Also I suppose that a lower rated petrol than 95 may be available in some countries and using that would not actually be advisable.

I was in Florida couple of years ago and their unleaded was all the way down to 91 RON or so. Cried when I saw how cheap it was...