It was just a though, that is all. However, their emissions figures do tell a different story. We usually do a four gas test on an MOT and the Lambda reading is normally to within a couple of thousandths of a percent off perfect.
Hmmm, that seems to figure though, many older cars seemed much less fussy about fuel quality.
Are you now claiming their petrol engines produce less emissions than any other?
The SD1 EFI produces pretty good emission figures for a non cat. car. About 1-1.5% CO.
However, you suggested incomplete burning of the fuel was the reason why other cars suffered more with Shell petrols than Honda? Now the main symptom of incomplete burning is high CO production.
No.
No, I suggested (and I quote 'I would guess', it was just that a guess, a suggestion, not a quote or a known fact, OK?) the incomplete burning was why other cars suffered *less* than Hondas. That in itself was over simplification though.
There are many symptoms of incomplete burning, CO is only one that was used for measuring mixture for tuning purposes. If you want a truly accurate mixture setting you need to use Lambda calculation ( a perfect reading being 1.0). Incomplete burning mainly produces HC, and you can also measure poor burn by increased O2 as well, or a decrease of CO2.
The older engines that have incomplete burn simply cannot use all of the fuel, and air, that is in the combustion chamber. By running a slightly richer than perfect mixture the cylinder ran slightly cooler, which was suitable for the materials available at the time. Of course running hotter also produces Oxides of Nitrogen, which are very poisonous, and is why most cars now use an EGR system.
Current Hondas, and I would also guess a lot of other modern cars, run at almost perfect stoichiometric mixture. Materials have advanced enough to cope with the temperatures. EGR valves control the poisonous stuff. They use just about all of the fuel and air that has been induced leaving none to burn excess chemicals. That at least is my guess, and I would accept any information that proves otherwise.
Some models of Honda can actually exceed the emissions legislation without the cat being fitted. They have to have the cat to meet the legislation nonetheless. In fact they had an engine in a production Civic in 1991 that could exceed the Californian regulations without a cat being fitted.
Unless they're *really* stupid, Shell obviously haven't found this in their testing, so I wonder whether it's influenced by the usage cycle; are these short journey cars, high milers, thrash the nuts off it drivers?
They should do, really.
There doesn't seem to be any real pattern with this in that respect, it has affected driving styles of all kinds. Lower mileage cars are a high percentage of our database, so it would be hard to make any assumptions from that, they are bound to have a higher percentage of problems.
Of course, although from a world wide point of view the UK is pretty small for Honda, so redesigning and engine for us isn't really worthwhile.
Worrying. And this has affected a range of engines? I wouldn't be surprised to find that a large proportion of Type-R and S2000 engines are run on nothing else.
I wouldn't expect them to redesign the engine if the fault is with the fuel, and given that Honda makes more IC engines than anybody else, they should have a pretty good idea of how to do it properly. A press release might reduce their warranty claim costs, though.
Quite possibly, although now I think about it, those are probably to only two models that don't seem as prone to problems.
That's true of course, although at the moment, as far as I know, there isn't any offical stance on this, and I suspect a large legal wrangle is something both parties might want to avoid.
As it is, most of the problems we get occur outside the warranty period.
That's a little reassuring. I run the Civic on Optimax when I can engineer being close to a Shell station for filling, 97RON otherwise,
95RON if I'm feeling cheap. It does statistically significantly better MPG on Optimax than on 95RON, so I assumed that it liked it.Understandable, if slightly depressing.
Is that outside of three years, or is the Honda warranty one year and the rest dealer warranty?
Does it make up for the extra pence per litre though? I suspect not.
Three years, Honda has full factory warranty for that time.
No, it doesn't. A couple of mpg driving it normally, difference between averaging 27 and 29. Deliberately driving it gently makes a much bigger difference; if I drive like a nun, it will do 35mpg on the same cycle.
I've just checked the spreadsheet, and the comparison was actually between [Optimax] and [not Optimax], a mixture of mostly 97RON and some
95, calculating what % of the stuff was left in the tank and correlating it with mpg on that fill.It does feel quicker on it, but that's so subjective and prone to suggestion that I wouldn't trust it.
So not really worth the bother then :-)
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