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We own a 1.6 grand Cmax . The last time we drove to Cornwall it was down to third gear on some of the long A road drags.
I vowed that next time we would hire a nice powerful car. Having seem the price of car hire I got to thinking if premium petrol would improve its performance on the big hills?
Would it make any difference ?
Ummmm......... not really, no!
Absolutely none. Can make a small percentage difference in cars with turbos and decent power already.
Could you get it remapped ?
My i20 needed first gear for some of the hills last summer.
It's not very well...
I doubt it would make much difference, other than better economy. I get 10% better fuel on a run with E5 Super than E10. If the car is fully loaded, you'll need to keep the rev's in the power band for petrols.
Both our cars have the same power output, but mine is a 1.8 and MrsF's is 1.6. Same Manufacturer. My car is a bit heavier, but it's also quicker and has more torque due to the engine being a little bigger. Mine is also much better in the hills of North Wales and doesn't require the gear changes. The only time I've needed the gears is with four blokes and four trail bikes on the roof !
I understood that unless you went for the higher octane stuff then basically they were just normal fuel with a bit of detergent in to keep your engine internals a bit cleaner. Possibly noticeable over 50,000 miles but not to Cornwall and back. Even if you stuck with Shell Premium for 50,000 you probably have paid enough extra to have the whole engine replaced anyway, so as above, not really worth it.
When I had a puma years back I sometimes put posh petrol in. It made a small improvement in fuel economy but not enough to cover the extra cost. No noticeable change in performance when driving. It’s basically snake oil isn’t it?
🤣 having similar concerns with my old 1.6 zafira that will be loaded with camping gear, bikes, and people when we go down there this summer. Its flat as a fart at the best of times, but any hills or load on board and you've just got to be patient and not even consider overtaking anything 🤣
What about putting some in diesel for extra torque on the hills?(!)
Having seem the price of car hire I got to thinking if premium petrol would improve its performance on the big hills?
No. High performance cars are sometimes tuned to take advantage of it and will have to fall back to safer settings when using normal petrol. If you have such a car, it will reach its full performance on higher octane petrol, but it'll make no difference in a normal car.
It’s basically snake oil isn’t it?
Well no, insofar as it's a real thing, it is higher octane and it does have cleaners in it. The marketing is way off the mark though and is very misleading.
flip side is i disagree on a long run youll recover the cost of premium fuel easily. However it wont give you +100hp that you require.
Posh petrol will make no difference to power output of a normally aspirated (non-turbo) petrol engine :o(
It's Cornwall not the Alps - there's a few drags but you just go slow on those bits!
And there will be a stream of campers and caravans going slower than you! 🙂
Slightly different story with diesel though - fancier diesel does run a little bit better in all diesels, but not a lot. It does clean up your engine slightly, it'll start better and run somewhat smoother, but in a newer car they are so smooth anyway it doesn't make that much difference.
My own experience was a few more mpg which meant the same cost per mile. No noticeable performance benefit.
Could you get it remapped ?
No point on an NA petrol.
Now an engine swap with an ST170, hmmmm.
I put a couple of tanks of posh diesel through my (diesel 🙂 ) van annually. I hope that the injectors appreciate the gesture, no power difference noted
See thats where a bigger engine car would be more economical on motorways etc.
I always used to have small engined cars, then got a 2.0 diesel. Wouldnt go for a small output (power) engine again as they use more fuel and less comfortable to drive... apart form around town.
In performance engines I try to avoid supermarket fuel, usually filling up at a local relatively competitive shell but with 95 octane. I run a tank of Shell V-Power through every 3-5000 miles as I believe the additional additives help clean the injection system. For track days, I always use whatever Super Unleaded is available as it does protect the engine under continuous abuse (especially motorbikes) and the modest performance gain becomes noticeable.
If you have a vehicle you're going to leave unused for many months, it's not a great idea to leave E10 in the system as it absorbs water faster and the additional solvents can damage the injection system.
In a vehicle with a regular engine, I just run what's cheapest. I think it's probably more important to not run to near empty, so you don't bring up whatever containments in the tank that are floating at the top.
No difference in power. Did however give me 49.7 MPG on a 500 mile motorway haul, up on 44.3 MPG on the (slower) outward trip using E10. effectively an additional 75 miles before the light went on.
In a vehicle with a regular engine, I just run what’s cheapest. I think it’s probably more important to not run to near empty, so you don’t bring up whatever containments in the tank that are floating at the top.
I usually use BP/Shell etc. But in the last few months its been about 20p per ltr more than a local independent garage. Using their fuel economy dropped immediately from roughly 49mpg to about 42 mpg. I imagine if I used super dooper fuel it would go up in to mid 50's
Every so often I use posh stuff as it does clean the engine a little.
Just a thought - How old is the C-Max?
I drive a 15yr old Type R and it runs a lot better on premium fuel (E5) than the new E10 unleaded.
Just a thought – How old is the C-Max?
2012
Just take a run-up!
Don’t know about posh petrol, but my old 1.8 cmax (2004 vintage so could be different to yours) did not like supermarket petrol at all. I never bothered with the fancy stuff, but had to swap to shell/BP or similar otherwise it bogged down horribly and was awful pulling away if you were in a hurry
I'd be looking at whether anything is hindering the car. Incorrect fuel mixture, vacuum leaks, etc. Most modern cars will tell you this.
Then I'd give it a good service, air filters, plugs etc.
In reality you probably want a more powerful car.
See thats where a bigger engine car would be more economical on motorways etc.
Not convinced by that. Of course diesels are more efficient, but a larger NA petrol engine is not likely to be more efficient than a smaller one on motorways, provided it has high enough gears. Small displacement, lower revs and a wider throttle is probably the most efficient way to burn petrol without a turbo, I'd guess.
twas obvious i'd pop in....
I get 10% better fuel on a run with E5 Super than E10.
These figures are always difficult to quantify, as the effect is not always down to what you think the cause is.
Ethanol has ~30% less energy density to it, so the extra 5% is only 2.5% less energy density in an E10 over an E5 -we measure these things as LHV (Lower Heating value) - so to get 10% improvment is not possible notwithstanding other factors..
other factors..
Liquid density - 2 x fuels with a comparable liquid density say 0.735, one E5 one E10 you will see a slight drop -10% is still a high figure. However, take the E10 with a higher density, say 0.75 (this may seem small but it's not) and your volumetric energy density is actually greater than that of the E5 - and this is what the car can make use of.
Additive packs - there a re 2 types - Keep clean and Get clean, with the later being reerved for premium fuels i.e. vpower types. These will arguably have a greater impact on the perfromance of the vehicle, oftern restoring it to t's original optimised performance (clean valves and injectors), and in some cases prioviding a benefit through flame modification additives (i.e. you can modufy flame speed in combustion making it more efficient).
Octane - not the bee all and end all of fuel quality, far from it actually its nothing more than a knock indicator. Most cars will have traditional maps for 95-97RON, some will have one for 100RON, but certainly nothing over that. They will also have protection maps for ~93RON in the UK. The ECU's will leean, or use Lambda sensors to adjust timing -efficiency gains are had when the combustion can start as close to "top dead centre" of the stroke - higher quality fuels allow this to happen -especialy knock resitance - if you try to achieve TDC with a low octane fuel you can get knock/detonation and destroy piston heads and or valves. However Octane doesn;t exist in fuels as singluar number, it's made up from 200+ chemicals that all contrbute, and those chemicals atomise and burn and different speeds -so a 98RON Octane in one fuel may not be as good at avoiding knock of 98RN in another fuel.
there's todays chemistry and engineering lesson.
Just take a run-up!
Used to do that in my old 1000cc Mini (proper one!) - you'd rag the arse of it on the downs. Speedo needle hitting the limiter pin then rapidly go down the gears when the uppy bit started! 🤣
back to the point anyway.
under constant high loads you should always use a fuel with good cleaning performance. High load applicaitons cause depositis very quickly, which will either sit on valves (ecpecially in PFI engines), or on injectors becuase they stay very hot posh fuel will assit with this. On the point of a hot engine, Ethanol has a positive impact from its charge cooling effect so can help with heat managment. - Anyway, just use a decent branded fuel - just avoid the very cheap supermarlet ones as they skimp on the add packs.
edited for a freuding slip
Posh petrol will not solve the issue of a steep hill and a heavily loaded and modestly powered car.
back to the point anyway.
under constant high loads you should always use a fuel with good cleaning performance.
Great info, thanks @Sui.
So when I'm towing a 2.5 ton load 120 miles should I ideally be using 'premium' fuel [3.0L diesel] - I try to get my fuel from Costco as it's not only cheaper but, they say, it's good quality* also.
* May not not actually be true
Just a well known brand (Shell, BP, Total, Esso) will do the job @sharkbait - im not sure what Costco's supply/spec is like (didnt even know they did it tbh)
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<div class="bbp-reply-content">Posh petrol will not solve the issue of a steep hill and a heavily loaded and modestly powered car.
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it will certainly protect the car over an above non-posh fuel (i.e. supermarket)
I don't get a noticeable performance increase in my 2l NA petrol. But the fuel economy increase is more than equal to the extra cost. A good extra 50 miles from a 40L tank
Even if you stuck with Shell Premium for 50,000 you probably have paid enough extra to have the whole engine replaced anyway, so as above, not really worth it.
Because I like playing with numbers, using some average numbers
Normal fuel = £1.70 per litre
Premium fuel = £1.90 per litre
Assumed MPG = 50
Over 50,000 miles, the premium fuel would cost £909 extra, assuming no change to fuel economy. A 5% improvement in fuel economy would reduce the difference to £497
I notice a performance and fuel economy difference. I tend to only use “posh fuel”. I do have a performance engine though. I also use Redex every 1000 miles or so.
I tend to do a fair bit of motorway driving, I don’t speed but can get up to the speed limit reasonably quickly.
Whether or not it’s worth it is a different question. I’m happy to think that my engine is getting the cleanest fuel it can have.
Normal fuel = £1.70 per litre
Premium fuel = £1.90 per litre
With peoples estimates in previous posts of about 10% extra fuel economy, at best the posh petrol nearly pays for itself.
So WHY BOTHER?
My car does run appreciably smoother and uses a little less fuel with Super Unleaded, particularly Tesco 99ron momentum. But it is a turbo and the manual advises 98ron. It will run on 95 and I don’t worry if I have to use it, so much of the time I guess it is running on about 97ron. Whether the smoothness is due to the higher Ron or the reduced ethanol I wouldn’t like to say.
Just a well known brand (Shell, BP, Total, Esso) will do the job @sharkbait – im not sure what Costco’s supply/spec is like (didnt even know they did it tbh)
Unless you live in Scotland in which case your petrol came through the INEOS refinery at Grangemuoth no matter what the petrol station is branded...
As for the rest if the UK only EXXON in the above list has a refinery in the UK. Do you relly think that those other companies ship their fuel from their refineries abroad or do you think they just buy it wholesale?
If you are just looking for a bit more pep uphill I suggest a Car Nitrous Kits from Wizards of NOS. That'll do it. Big red button to push anytime you need a boost. Bolt on and at least another 50bhp under you bonnet.
Coincidentally I read this yesterday
Unless you live in Scotland in which case your petrol came through the INEOS refinery at Grangemuoth no matter what the petrol station is branded…
As for the rest if the UK only EXXON in the above list has a refinery in the UK. Do you relly think that those other companies ship their fuel from their refineries abroad or do you think they just buy it wholesale?
The UK is a net importer of fuel, and Fawley (Exxon) is not the only operational refinery in the UK at all -there are 6 - and yes everyone ships everything everywhere - its a very complex model operating at very thin margins, so shipping of a boat and then bringing in a boat really does happen. Base quality of fuel does change all over the UK, as such the add pack treatment rates also change depending on where the base material comes from (to an extent).
To this using redex type things on top of premium fuels -you really shouldn't, you're overdosing and can form "gumming" as a consequence.
Unless you live in Scotland in which case your petrol came through the INEOS refinery at Grangemuoth no matter what the petrol station is branded…
It doesn't matter if it all comes from the same refinery. Different customers have different additive packs added, at the refinery I think.
I predict this thread will be longer than the delay the OP has being a bit slower up a couple of hills 😀