4.2 XKR / XKR regular or super fuel?
Discussion
I tried 1000 miles on 98 octane fuel in my v8 xj and found absolutely no difference in performance or economy. You're almost certainly better off spending the extra money on synthetic engine oil to gain the reduction in friction and more effective heat transfer that will improve power output and economy.
I always use V-Power or BP Ultimate, always let the engine warm up before moving off, always have the cars serviced regularly, check oil, water pressures. Cars run like a dream, sing like angels and engine condition is A1, according to the guys who service them. Wouldn't dream of using standard fuel in an XK but you do what you are comfortable with.
Ecurie Ecosse said:
phumy said:
Ecurie Ecosse said:
I use V Power in my X308 XJR and can feel a difference.
The knock senses it is there. Well worth the small £3ish difference per tank - better detergents etc too.
What is the "knock"?????The knock senses it is there. Well worth the small £3ish difference per tank - better detergents etc too.
"always let the engine warm up before moving off"
I was always told this is a very bad idea. You are much better off pulling away asap and letting the car warm up as you drive. True you should not start "pushing on "
until warm but even apart from the waste of fuel I though driving got the oil etc. circulated better ?
I was always told this is a very bad idea. You are much better off pulling away asap and letting the car warm up as you drive. True you should not start "pushing on "
until warm but even apart from the waste of fuel I though driving got the oil etc. circulated better ?Jackie Stewart 'Principles of Performance Driving'.
If you want to drive off on a cold engine, go for it. Until the engine is warmed up it is not working to the correct tolerances. That is why racing engines are warmed up before they are put under load. The age of an engine is defined by number of cold starts carried out, not miles covered. All this tripe about driving off immediately is encouraged by the do gooders for supposed economy and pollution reasons, and done because most people are too lazy to bother. In reality it is just increasing your engine wear. An engine in good condition will always however deliver better fuel consumption.
As far as using premium fuels is concerned the best one available in this country is Shell V Power, and consistent use will undoubtedly benefit the engine. I can certainly feel the difference, though not so much as I can with the old Aral Super Plus 100 in Germany, now much less easily available. Tomorrow I will let you know what the XKR handbook says, but I really can't see the point in putting standard fuel into a high performance engine to save, what, 7p a litre.
However, if the OP wants to do it, I can't stop him.
If you want to drive off on a cold engine, go for it. Until the engine is warmed up it is not working to the correct tolerances. That is why racing engines are warmed up before they are put under load. The age of an engine is defined by number of cold starts carried out, not miles covered. All this tripe about driving off immediately is encouraged by the do gooders for supposed economy and pollution reasons, and done because most people are too lazy to bother. In reality it is just increasing your engine wear. An engine in good condition will always however deliver better fuel consumption.
As far as using premium fuels is concerned the best one available in this country is Shell V Power, and consistent use will undoubtedly benefit the engine. I can certainly feel the difference, though not so much as I can with the old Aral Super Plus 100 in Germany, now much less easily available. Tomorrow I will let you know what the XKR handbook says, but I really can't see the point in putting standard fuel into a high performance engine to save, what, 7p a litre.
However, if the OP wants to do it, I can't stop him.
cardigankid said:
Jackie Stewart 'Principles of Performance Driving'.
If you want to drive off on a cold engine, go for it. Until the engine is warmed up it is not working to the correct tolerances. That is why racing engines are warmed up before they are put under load. The age of an engine is defined by number of cold starts carried out, not miles covered. All this tripe about driving off immediately is encouraged by the do gooders for supposed economy and pollution reasons, and done because most people are too lazy to bother. In reality it is just increasing your engine wear. An engine in good condition will always however deliver better fuel consumption.
As far as using premium fuels is concerned the best one available in this country is Shell V Power, and consistent use will undoubtedly benefit the engine. I can certainly feel the difference, though not so much as I can with the old Aral Super Plus 100 in Germany, now much less easily available. Tomorrow I will let you know what the XKR handbook says, but I really can't see the point in putting standard fuel into a high performance engine to save, what, 7p a litre.
However, if the OP wants to do it, I can't stop him.
The OP hasnt said he is doing anything, he was asking a quaestion.....If you want to drive off on a cold engine, go for it. Until the engine is warmed up it is not working to the correct tolerances. That is why racing engines are warmed up before they are put under load. The age of an engine is defined by number of cold starts carried out, not miles covered. All this tripe about driving off immediately is encouraged by the do gooders for supposed economy and pollution reasons, and done because most people are too lazy to bother. In reality it is just increasing your engine wear. An engine in good condition will always however deliver better fuel consumption.
As far as using premium fuels is concerned the best one available in this country is Shell V Power, and consistent use will undoubtedly benefit the engine. I can certainly feel the difference, though not so much as I can with the old Aral Super Plus 100 in Germany, now much less easily available. Tomorrow I will let you know what the XKR handbook says, but I really can't see the point in putting standard fuel into a high performance engine to save, what, 7p a litre.
However, if the OP wants to do it, I can't stop him.
As for the fuel grade it really doesnt matter what you put in it, the ECU will take cre of the rest for you so there really is no need to be wasting 7p a litre. The engine would possibly be 2 or 3bhp down by using a lower octane fuel, you wouldnt even feel the difference in normal driving.....You are only kidding yourself.
phumy said:
As for the fuel grade it really doesnt matter what you put in it, the ECU will take cre of the rest for you so there really is no need to be wasting 7p a litre.
The engine would possibly be 2 or 3bhp down by using a lower octane fuel, you wouldnt even feel the difference in normal driving.....You are only kidding yourself.
I agree with you thereThe engine would possibly be 2 or 3bhp down by using a lower octane fuel, you wouldnt even feel the difference in normal driving.....You are only kidding yourself.
I use Sainsbury's they are just a mile from home and the cheepist in the area
In fact I have a booklet of all their outlets and if on a long trip have to refill I'll refer to that if there is one close to where I'll be, usually find one just off the motorway or main road so have from the overcharged motor way services
Benbay001 said:
cardigankid said:
You are right, of course, that's why they do that with Formula 1 engines, just drive straight off. How could I be so silly?
Yeh, i warm my tyres before my commute too. You would be silly not to.Or have i missed a wink there..
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