Apologies if this is has been discussed on here previously, but my guess is that under normal circumstances we shouldn't be using E10 petrol in any BX. Would that be the general consensus?
Knowing that my local Esso had E5* pumps I filled the BX up with that, but the cost! £7.55 per gallon or £1.659 per litre which is by far and away the most expensive petrol I've ever put in a car. I will be interested to see how well it goes
Obviously I need to research more keenly priced petrol, but can any one recommend any good websites/apps listing garages with E5 petrol and prices?
*According to Esso there is in certain areas of the UK there is actually no ethanol in their E5 petrol.
1991 BX GTi auto, grey, 137,000 miles (2015, 2017 & 2019 Citroen Classic Challenge veteran)
1991 BX GTi auto, grey, 85,000 miles
2006 C4 VTR+ 2.0 Coupé, silver, 73,000 miles
From the point of view of engine performance, an engine with a catalytic convertor and oxygen sensor should be able to automatically cope with the mixture adjustment for E10, and no difference should be noticed other than a slight worsening of fuel economy and perhaps a little hesitation when the engine is cold.
Engines without closed loop mixture control will run a little lean, the effects of this depend on how the engine was originally tuned. On a fuel injected engine this may be compensated by a slight increase in fuel pressure. A carburetted engine would require re-jetting to correct.
Note that some of the price differential for E fuels is due to reduced excise duty.
Thanks, as few BXs have catalytic convertors, to the layman (such as me!) are you saying that for a GTi it could be OK and that there would be minimal risk of damage? Or might it be acceptable to alternate tanks of E5 and E10?
My main driver is not so much cost but what it best for the BX.
1991 BX GTi auto, grey, 137,000 miles (2015, 2017 & 2019 Citroen Classic Challenge veteran)
1991 BX GTi auto, grey, 85,000 miles
2006 C4 VTR+ 2.0 Coupé, silver, 73,000 miles
Ethanol itself is a good fuel, but it has less calorific value than straight petrol, so it burns lean. To put it another way, if an engine is drawing in the same amount of air, it needs more fuel to get the correct fuel/air ratio. From memory, it takes about 4% more E10 than straight petrol to get the same power output.
Ethanol is also hygroscopic so will hold water, which if left sitting for long periods can cause corrosion of alloy fuel system components.
If the car is in regular use, I would get it tuned (if necessary) for E10. If it is more a garage ornament, then I would live with the cost of E5 (although that may disappear in a year or two).
I think that the GTI was always injected, but I am not sure which injection system was fitted. If it is one of the Bosch systems with manifold corrected fuel pressure regulators, it is usually possible to fit an uprated or adjustable pressure regulator to suit a lower calorific fuel. I have fitted 3.5 bar regulators (genuine Bosch) to a couple of my cars in France where E10 has been the norm for several years.
For the limited mileage a BX would normally do, I'd stick with E5 personally. I'd only use E10 if I had a leggier one than I was running as my only car.
The 16v is designed for four-star! That's got it even worse!
I can remember asking my dad years ago what the difference was between 2** and 4**** petrol and his answer was 4**** was for men and 2** was for women.
90 BX Tzd turbo 294k SORN undergoing major surgery
90 BX Tzd turbo estate 46k awaiting surgery
65 Peugeot Boxer Van the new workhorse
52 Toyota Rav4 180k Bulletproof Jap reliability
I've been running the BX on E10 ever since it was introduced. It's running well on it, so far.
The Solex 32/34 carburettor I installed yesterday came from Spain, which must have been using E10 a fair while before us. The bottom of the fuel bowls, accelerator pump and power valve were filled with corrosion. It also stunk of old petrol, so it clearly was sitting on a shelf for a long time.
Maybe coincidental, but our local garages only have e10 now, since then my daughters Nissan Juke (Which has always started faultlessly) has taken quite a lot longer to start on several occasions. It may be a fault looming or e10 syndrome. Only time will tell.
90 BX Tzd turbo 294k SORN undergoing major surgery
90 BX Tzd turbo estate 46k awaiting surgery
65 Peugeot Boxer Van the new workhorse
52 Toyota Rav4 180k Bulletproof Jap reliability
On a somewhat related topic the carb on my BX 16 TGS has a label 'E10'.
Is this just coincidence or were Citroen ahead of the game in 1992 and already planning for ethanol content?
Oh, that's what the silver label is supposed to say! I stuck one of those carbs with a manual choke on my BX 14 a couple weeks ago and I couldn't make out what it said.
10:1 CR iirc.
