Now I know it usually gets a bad rap and is blamed for everything from the neighbours budgie dying downwards, but it seems the BeCM is actually a pretty clever little beastie. Last weekend I had to tow this to just north of Toulouse

Not only is it 9 feet tall and 6 feet wide, so acts as a braking parachute in a headwind, it was also well loaded so almost at it's maximum weight of 3.5 Tonnes. The weekend coincided with Storm Diana hitting the south of England and most of France too which meant two things, the channel crossing was going to be rough and once the other side I'd have a hell of a headwind. Also the route includes some pretty serious hills both up and down. So, rather than risk being rammed up the back by an empty artic who may not realise the speed differential while I was slogging up a hill in the dark, I put a magnetic 55W halogen amber beacon on one side of the trailer. The trailer has a junction box near the back where all the wiring connects so it was easy enough to connect the beacon to one of the sidelight circuits in there.

About 20 miles from Dover, I get a beep from the dash and the message centre comes up with RH Tail Light Bulb Blown but a few minutes later I notice that the LH side marker lights and beacon had gone out on the trailer. Switched the lights off and back on again and everything came back on. Seems that the extra load of the beacon on one sidelight circuit had been seen, eventually, by the BeCM as a short circuit bulb which would only happen if the bulb had blown so it had switched that circuit off to prevent the possibility of further damage in lieu of there being a fuse in the sidelight circuit. When I next stopped I ran a wire from the beacon to the ignition switched supply in the boot but it did prove that the trailer lights were wired back to front so the LH and RH circuits were crossed I was more impressed with the way the BeCM cuts power to a circuit it detects a problem on, so not so dumb as many seem to think it is.

Incidentally, I took the picture in my avatar on the way back but what was most interesting was the difference between the run there, against the wind with the trailer and coming back with the wind behind me and no trailer. Trip out, average speed 43 mph at 12mpg, coming back, average speed 67mph at 17.2mpg. Seems aerodynamics, or a lack of them, make a hell of a difference......

Most of the lamps in the BECM are driven by MOSFETs which use the status line to give a fault condition to the BECM (which sees that as a lamp failure). But the FETs also have internal protection for thing like reverse voltage, short circuit and over current aswell, and the 'under minimum load' which is the normal condition for triggering the bulb failure message.

Interesting just how much of a difference the trailer made!

I’ve always found that my best mpg is above 70mph, especially when I had the dse, I think on low revs our cars are always Labouring a bit, but once up on the revs they just purr along

Yep tend to agree. I get high teens on the motorway at around a bit over 70! :-) if in the 50mph bits it’s good but doesn’t like the 60-65mph.

I've always been led to believe that an engine is running at it's most efficient, and therefore most economical, at the revs where it produces maximum torque. Having just done a quick Google, it seems maximum torque is produced around 2,600 rpm which would equate to around 75 mph. Despite having the aerodynamics of a shed......

I've just done Winsford to Rochechouart twice in 8 weeks, 27.8mpg with no trailer but very heavy load in the back, 20.1mpg with my twin axle trailer and a flatpack kitchen in it. Drove down last Saturday and the weather was awful all the way down fighting the storm so I'll measure my mpg with an empty trailer on the way back. I might fit a yellow beacon next time, French drivers love screaming straight up to the back of you - especially artic trucks - and flashing you to shift. A bit hard when you are halfway past a lumbering artic though, it's not like I can suddenly drop backwards or light up my RATO pack to assist. hahahaha

27 mpg isn't back for an oil burner, don't forget I'm a V8 but running LPG so on near half price fuel. Not that you would notice that in France, 1 Euro a litre at a couple of the motorway services! Petrol and diesel are also stupidly expensive too, not surprised the natives are revolting.

We went down to Sicily in September on a 'Thelma and Louise ' road trip. Using 90% national roads i averaged 31.9. Mind you, we took 10 days to get there! We enjoyed ourselves so much, we have come down again!! Got here last Friday and we're here for Xmas and then up to Bergamo for New Year to visit the sister in law. This time we used motorways the whole way. I was disappointed to only get 26.8 this time. A possibility is doing an average 75-80 most of the way.

Bet it didn’t take 10 days though, lol, that’s not a bad mpg .

no10chris wrote:

Bet it didn’t take 10 days though, lol, that’s not a bad mpg .

On reflection, a V8 returning those figures whilst running at 75-80 for miles on end isn't bad. But I was expecting better seeing as it was constant motorway. By the way, it took us three and a half days.
The bummer is I can't use cruise control!! This model has ACC (active cruise control) and it's bloody lethal!! I asked the garage to disconnect it earlier this year when they did repairs to the front end but they couldn't as it would throw a fault.

What's lethal about it? I love cruise control, in my experience the car just plods along.

RutlandRover wrote:

What's lethal about it? I love cruise control, in my experience the car just plods along.

I love cruise control too. Have you ever used Active Cruise Control?? You set the speed and off you go. Only, if you start catching something up, it slows you down! The idea is you won't run up the arse of the vehicle in front. That's all well and good but if you're catching up quickly, the braking is quite violent. Also, if you are trying to pull out to overtake, the car passing you goes by. You pull out but if you're too close, it will brake you down which doesn't make you popular with cars now behind you. I've now decided the UK motorways are too busy to use it. The only time I use it is when there is nothing about.

Ah, I see. I've never used it myself but I have been in a Volvo with it.

Plenty of random emergency stops driving through residential areas past parked cars. Not using cruise control but the object detection is the same.

You don't have a P38 then?

I've had four but bought this baby 18 months ago ( Sport with the Stormer bodykit ). I still sometimes regret selling my last 38 as it was a damned good one. I believe Gilberts pal is still driving around in it.

I've fallen foul of the lack of signatures on mobile again. If I switch to desktop view it's obvious what you've got!

How does it compare to the P38?

Yup, OldShep's P38 was bought by one of my neighbours at the last house. He's still loving it even if he has got an intermittent boot release so he's got used to dropping the rear seat and getting in through there. He's bringing it round after Christmas so we can see if it's the button or the latch that only works sometimes. I suspect his new one is going to be a bit quicker with the TDV8 under the bonnet and in grey with the Stormer kit it's one of the few Sports that doesn't look dated.

Seems P38s BCMs are better than Vauxhall ones.
My son was setting off to work the other morning, got in his Astra, turned the dipped beam on, both bulbs lit but went out after a second and wouldn't come back on again. Side lights and main beam worked as normal. No fuses or relays to check.
They were broke for a few days, fixed now but all he did was change the bulbs without testing them. Says the bulbs look fine and it would be a hell of a coincidence for both bulbs to blow at exactly the same time and not look blown.
Having done a bit of research it seems it isn't unknown for this to happen on Vauxhalls and simply removing bulbs for a while and refitting effects a cure.

Which reminds me, I once bought my dad a gas discharge bulb mod for his Vectra. Wired it all in but it caused the lights to flicker dimly at about 10hz and the bulb warning on the dash to come on. I ended up wiring some sidelight bulbs in parallel with the bulbs high voltage conversion units to get around all the problems. At least on the Vectra bulbs are changed from inside the engine bay, as opposed to the Astra method of accessing bulbs blind from a removed section of the wheel arch liner using a torx bit.