Drive a Zafira 1.6? Get 7 more mpg!

MikeHiow said:
Given how much people slate Vauxhall on here, and that the VXR is 'mapped' for 98/99RON, I find it amusing how many people are inadvertently defending them here, by claiming you couldn't possibly lose 22% in fuel economy by switching from the recommended fuel.
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Ouch, now you're really clutching at straws.

Mike why not do a proper brim--brim test to prove all these jokers wrong?
 
Mike you have completely missed the problems that people have with this "research". The issue we have is that it is so utterly far from thorough and scientifically strong. They have about as much evidence for this as they do for the statement "Tesco super unleaded will make your car twice as fast, twice as economical, and give you a blowjob, it's also 90% of the way to curing cancer." They may as well have plucked figures out of this air (which, let's face it, it looks like they have done) as done such a flawed test.

I doubt very much that everyone on the forum thinks that high octane fuel is a waste of time, it will be an advantage in cars which have a map optimised to run on such fuel. As it stands a low powered shopping trolley won't benefit from running higher octane fuel, if you wish to dispute that then get some proper research done, this absolute joke from Thorney and Tesco does not even come close to proving that their fuel is of any benefit.
 
I'm not saying its accurate, but the basic finding stands true, that is there are gains to be had. I said clearly that I was going to neither discredit, nor promote their findings, just that its entirely possible that they are reasonably fair.

Having an idea of how engines work, I see no reason why a low powered car wont' benefit from running a higher octane fuel, and this is half the problem - most people are arguing their point based on stuff they've read about 15 year old Japanese turbo cars (ie. A car needs to be mapped to benefit from higher octanes etc.).

Modern engine control systems can and do adjust ignition timing (possibly amongst other things) to suit the fuel being used, so with that in mind, its entirely possible that a low powered shopping car could see some benefit from running better fuels.
 
98 plate Saxo engine didn't really see an increase, perhaps 1mpg

03 Plate Clio engine didn't really see an increase, perhaps 1mpg

99 plate MX-5 engine didn't really see an increase, perhaps 1mpg

01 plate Passat engine didn't really see an increase, perhaps 2mpg

The main fact is the Passat and MX-5 both felt down on power and throttle response when running 95 over 99.
 
Both of us are guessing here, but it is logical that something at least 10 years newer is going to be more advanced. Your car pre-dates the wide use of CANBUS ffs.
 
Whats the wide use of CANBUS got to do with anything, i'm talking about the 1.8T engine and ECU i'm not talking about anything else that was around at the time.

Would you please detail to me which aspects of the i10 ecu are more advanced that the Bosche Motronics one found in the later 1.8T aplications 2001 - 2005.
 
MikeHiow said:
Modern engine control systems can and do adjust ignition timing (possibly amongst other things) to suit the fuel being used, so with that in mind, its entirely possible that a low powered shopping car could see some benefit from running better fuels.
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Not to the extent you are imagining though!

What else would they adjust other than spark and fuelling, fuelling is only based on the lambda closed loop feedback of the air fuel ratio either side of 14.7:1 AFR by mass so the Super Unleaded does not change that relationship.

Your points on ECU's are silly. OEMs buy stuff from a supplier based on the requirements they need and driving pence out of each part. An i10 ECU needs less features than a VAG 1.8T and hence it will have less.

My ECU is 1999... gonna argue the i10 has more going on than that one ;) Wideband Lambda sensor for a start will not be on an i10.
 
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Jonnycoupe said:
Your points on ECU's are silly. OEMs buy stuff from a supplier based on the requirements they need and driving pence out of each part. An i10 ECU needs less features than a VAG 1.8T and hence it will have less.

My ECU is 1999... gonna argue the i10 has more going on than that one ;) Wideband Lambda sensor for a start will not be on an i10.
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Indeed, i could list a load of sensors and inputs that are needed to run a turbo engine that simply don't exist on the i10.
 
Jonnycoupe said:
Not to the extent you are imagining though!

What else would they adjust other than spark and fuelling, fuelling is only based on the lambda closed loop feedback of the air fuel ratio either side of 14.7:1 AFR by mass so the Super Unleaded does not change that relationship.

Your points on ECU's are silly. OEMs buy stuff from a supplier based on the requirements they need and driving pence out of each part. An i10 ECU needs less features than a VAG 1.8T and hence it will have less.

My ECU is 1999... gonna argue the i10 has more going on than that one ;) Wideband Lambda sensor for a start will not be on an i10.
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But I'm not talking about additional inputs, just improvements on basic ones (I'd be surprised if any cars these days didn't have some sort of knock detection), and differences in the what the ECU can do with that data.
 
I would imagine that as emissions controls have got much tighter, that ECUs have had to get a massively amount smarter/more powerful as no doubt emission reduction is largely about more sensors and control over the burn cycle (yeah, I made that term up just now!)..
 
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