1971 MGB GT - Trip to British Motor Museum - not 56k friendly - see page 39

[High Jetter]

53 minutes ago, vtec-e said:

Gunsons still make a Colortune

That's just reminded me, someone on the forum was going to send one to me ages ago - which I'd be happy to lend or pass on to @Peter C if required. Can't remember who it was though

[Dj_efk]

It sounds to me like you could do with balancing the carbs - a length of hose you can hold at at the mouth of each one with the other end stuck in your ear is all you need for this. A colour tune is  otherwise only useful if you have two - one for each pair of cylinders.

[High Jetter]

2 hours ago, Dj_efk said:

It sounds to me like you could do with balancing the carbs - a length of hose you can hold at at the mouth of each one with the other end stuck in your ear is all you need for this. A colour tune is  otherwise only useful if you have two - one for each pair of cylinders.

Colour tune is at the plug, not the carb. Yes, hose was the old trick.

[Peter C]

This wild MPG business has been bothering me ever since I did my man maths on Sunday afternoon. 

I took the MGB to another local Esso this evening.

Last time my fuel gauge was showing just over half (on Sunday, before my road trip), I managed to squeeze about 25 litres (4.5 gallons) into the tank.

I started to fill the tank today, to the point where fuel starting dribbling over the rear bumper and onto the ground.

And only 14.3 litres (just over 3 gallons) went in.

With the ignition switched on, the fuel gauge confirmed that the tank was full.

@Mr Pastry @LightBulbFun You were both absolutely right, the fuel gauge was telling porkies! 

So, if I clocked up approx 100 miles and used approx 3 gallons of fuel, that means that the MGB averaged approx 33MPG. Not 18! 

That's a very impressive figure, although it requires further verification as the exact amount of miles that I clocked up and the amount of fuel that I used is unknown. 

I have taken a mileage reading and will brim the tank again in approx 100 miles. Let's see what happens.

From the petrol station I went home via one junction of the M40. The engine ran fine but I have a feeling that it has less oomph at lower engine speeds. I might tweak the carb mixtures back up a little tomorrow.

I'm definitely winning.

More soon.

 

[chadders]

8 minutes ago, Peter C said:

This wild MPG business has been bothering me ever since I did my man maths on Sunday afternoon. 

I took the MGB to another local Esso this evening.

Last time my fuel gauge was showing just over half (on Sunday, before my road trip), I managed to squeeze about 25 litres (4.5 gallons) into the tank.

I started to fill the tank today, to the point where fuel starting dribbling over the rear bumper and onto the ground.

And only 14.3 litres (just over 3 gallons) went in.

With the ignition switched on, the fuel gauge confirmed that the tank was full.

@Mr Pastry @LightBulbFun You were both absolutely right, the fuel gauge was telling porkies! 

So, if I clocked up approx 100 miles and used approx 3 gallons of fuel, that means that the MGB averaged approx 33MPG. Not 18! 

That's a very impressive figure, although it requires further verification as the exact amount of miles that I clocked up and the amount of fuel that I used is unknown. 

I have taken a mileage reading and will brim the tank again in approx 100 miles. Let's see what happens.

From the petrol station I went home via one junction of the M40. The engine ran fine but I have a feeling that it has less oomph at lower engine speeds. I might tweak the carb mixtures back up a little tomorrow.

I'm definitely winning.

More soon.

 

25 litres is not 4.5 gallons, there are just over 4.5 litres to the gallon.

[Jazoli]

3 minutes ago, chadders said:

25 litres is not 4.5 gallons, there are just over 4.5 litres to the gallon.

Yup multiply the litres by 0.22, 5.5 Gallons

 

 

[Peter C]

Yeah, sorry, I meant 5.5 gallons. 100 miles divided by 5.5 gallons equals 18MPG, as reported on Sunday.

[Noel Tidybeard]

how far are you from Beko? he's got one of those suction gauges for balancing carbs that he uses on the vacuums

[Peter C]

5 minutes ago, Noel Tidybeard said:

how far are you from Beko? he's got one of those suction gauges for balancing carbs that he uses on the vacuums

@beko1987 How far am I from you?

[Dj_efk]

@Peter C you can buy a carb balancing tool cheaply enough - you need one if you’re keeping the MG

[Mr Pastry]

If that 33mpg is genuine and it performs well, there isn't much wrong with it.  Leave it well alone, and enjoy it.

[jim89]

2 hours ago, Peter C said:

Yeah, sorry, I meant 5.5 gallons. 100 miles divided by 5.5 gallons equals 18MPG, as reported on Sunday.

Yebbut your rebrimming sums are correct no? 100 miles, 14.29litres/3.2 gallons...  ~31.5mpg...?

[Christine]

 /\ whs ...The pump says 25 quid   , not 25 litres 

[jim89]

12 minutes ago, Christine said:

 /\ whs ...The pump says 25 quid   , not 25 litres 

To be fair @Peter C did have a schoolboy moment earlier confabulating his 25 litres w 4.5 gallons, but his sums on the refill look good to me (even if the figures are a tad unrefined as yet)👍🏻

[beko1987]

11 hours ago, Peter C said:

@beko1987 How far am I from you?

I'm in Thame. If I'm at the office it's even closer as that's in Marlow.

I do have a water lift gague, although no fittings or adapters (even I don't use it totally correctly tbh)

[Peter C]

At the Flower Farm soiree, @vtec-e had a good listen to the MGB's new sound system and enquired whether I put any wadding into the 6x9 speaker boxes. I hadn't. 

I had an opportunity to correct that today.

I removed the speakers from the boxes, to reveal nothing but two voids.

Rather than buying proper speaker wadding, I popped up into my roof void and nabbed a length of quilt insulation.

Which I stashed into the two speaker boxes.

I re-fitted the speakers, disconnected the other two amplifiers and had a listen to how the 6x9s perform now. It might be my imagination but the sound is significantly softer than before. Win.

Nice, no cost mod.

Thank you @vtec-e

[Christine]

Did you play Itchycoo Park  afterwards ?  

[Peter C]

11 minutes ago, Christine said:

Did you play Itchycoo Park  afterwards ?  

I’ve got that MP3 on my iPhone!

[Peter C]

Woke up this morning, picked up my phone, had a message from a client that I was supposed to be meeting with today, he had to postpone the appointment. This left me with almost nothing to do today. So, what does a cool bloke like me do on a Wednesday when he doesn't have work to do? Go to the British Motor Museum in Gaydon, of course.

The MGB is now my weapon of choice for most journeys and I had no doubts that it would make it there and back without any issues.

On route to Gaydon, traffic was very light. 

At times, I had the M40 all to myself.

Interesting things I saw on route:

1. Articulated lorries are overtaking other vehicles in lane 3 (of 3). I thought they were not allowed to drive in lane 3?

2. I saw a STGO Cat 3 with a dilapidated passenger train carriage on the back - very cool.

3. A Jenson Interceptor passed me. I gave the driver a little wave and a thumbs up whilst he was alongside me but despite the obvious similarities between our cars, the other driver failed to acknowledge my existence. Twat.

4. An Opel Astra, the same shape as what @lisbon_road has, on Ukrainian plates, drove past me with no less than 7 blokes on board - the driver, two guys in the front seat and four in the back. They all gave me a simultaneous thumbs up - nice.

Got to the museum and found a parking space right by the entrance, next to another similar car to mine.

The museum is great for anything MGB.

This was a safety test something or other prototype 'B, with bumpers even more hideous than the standard rubber ones.

Last ever produced MGB.

As well as other MG related stuff, including the first ever MG.

There's something for everyone at Gaydon.

A lovely Sierra XR4x4.

Early R50 MINI.

Something classy for @danthecapriman

The first ever driveable XK8 Jag - I've lost count how many members here have enjoyed the same blue XK8 and who owns it now but I recall that @gm had it at some point.

MGF coupe.

The MGF Metro test thing.

A two door Metro because the two door Vauxhall Nova wasn't shit enough.

What looks like an MG Metro Turbo is actually an MG Metro fitted with a prototype six cylinder engine. Shame the bonnet was shut.

One for @Wibble

One for @Lankytim and @Surface Rust

And a lot more.

I reckon there must be about 250 vehicles displayed in two buildings, across both levels. 

I was there for about three hours, then I headed home.

Just before I got home, I brimmed the tank again.

I squeezed in 18 litres.

I've done 152 miles since the last fill up.

18 litres = 4 gallons.

152 miles divided by 4 gallons = 38MPG

Admittedly, most of these miles were clocked up on the M40 today, at 55-60MPH with no traffic whatsoever but that's still a great result.

More soon.

 

 

 

 

[danthecapriman]

Nice stuff in the museum. Somewhere I really need to go one day.

38mpg sounds bloody good going honestly. I don’t think I’d get that out of my Capri and that’s 200 odd CC smaller. I’d be pretty pleased with your B if it’s returned that sort of figure.

[EspenO]

Obligatory Gaston Lagaffe is obligatory.

[vtec-e]

The carb set up must be pretty good to be getting 38 mpg. Probably worth whipping out the plugs before it is started up again and confirming. 

 

[Surface Rust]

2 hours ago, Peter C said:

A two door Metro because the two door Vauxhall Nova wasn't shit enough.

A grand day out.

I have a completely rational hatred of the Nova saloon, but I find that Metro quite appealing!

Must be the strong early eighties Alfa Giulietta design cues.

The greatest 'what might have been' for me was the Jaguar XJ40 shooting brake. Lovely.

[mercedade]

I really, really like the MGF coupe

[Dick Cheeseburger]

36 minutes ago, mercedade said:

I really, really like the MGF coupe

Agreed. Someone needs to build one from a TF. Such a pretty looking thing. 

I often wonder how many of the oddball motors inside Longbridge made it onto the road. 

[LightBulbFun]

On 06/05/2026 at 19:41, Peter C said:

At times, I had the M40 all to myself.

 going to the 1100 club gathering at the oxford bus museum a couple weeks back with my VDP1300, since I was setting out at silly-o-clock on a sunday, things where pretty quite, not that quiet mind, but I pretty much was had the outside lane of the M40 all to myself, and the few people who I encountered in the outside lane, or pulled in-front of me, curiously got out of the way quite quickly

maybe they could not quite comprehend "Grandads old car" skipping along at a good 70-75Mph!

On 06/05/2026 at 19:41, Peter C said:

I've done 152 miles since the last fill up.

18 litres = 4 gallons.

152 miles divided by 4 gallons = 38MPG

Admittedly, most of these miles were clocked up on the M40 today, at 55-60MPH with no traffic whatsoever but that's still a great result.

thats impressive! the VDP seems to get 25Mpg no matter what I do in terms of driving!

[Peter C]

5 minutes ago, LightBulbFun said:

thats impressive! the VDP seems to get 25Mpg no matter what I do in terms of driving!

You've answered your own question!

I pootled along in my 1.8 litre sports car at a steady 50-55MPH in sixth gear (if you count the overdrive ratios on 3rd and 4th gear) and got 38MPG.

You bombed down the M40 in your 1275cc 4 speed family hatchback at reckless velocity, exceeding the speed limit at times and got 25MPG!

[LightBulbFun]

35 minutes ago, Peter C said:

You've answered your own question!

I pootled along in my 1.8 litre sports car at a steady 50-55MPH in sixth gear (if you count the overdrive ratios on 3rd and 4th gear) and got 38MPG.

You bombed down the M40 in your 1275cc 4 speed family hatchback at reckless velocity, exceeding the speed limit at times and got 25MPG!

well surely for a suitable comparison then, you should do a run in the MGB at 70Mph cruise instead and see how much of a difference it makes?  

(will be interesting to see what MPG figures I get when I next fill the VDP up as the return trip back home on the M40 on that day was done at a more leisurely 60Mph pace)

I have found the Invacar to be surprisingly economical in that regard, even when relatively flat out on the Motorway, I still achieve a good 45Mpg! (& if we are counting gears like that, the Invacar has an infinite number of gears, until runs out of gears at 45Mph, then it drops into a fixed-ratio-overdrive mode where engine speed will increase with road speed ) 

 

also I wish the VDP was a Hatchback! do you know how much of a Pain in the arse it is trying to fill it up with 8ft fluorescent tubes otherwise?

 

[Peter C]

@LightBulbFun

My MGB feels perfectly civilised at a steady 55-60MPH and at those speeds, there is no need to crank up the sound system too high. However, those additional 10-15MPH make the experience of driving the MGB far less pleasant. The engine becomes more boomy and intrusive and the whole car feels like it is getting close to the limits of its abilities. Whilst driving slowly rewards me with great MPGs, I do feel like I am an obstacle and I tend to spend a lot of time looking in my rear view mirror at vehicles approaching much too quickly and getting much too close to the MGB's rump, simply because the drivers are not expecting a car to be driving that slowly on a motorway. 

The Mercedes Benz is a big (ish) and heavy (ish) car, with a 2.3 litre petrol engine, with mechanical fuel injection and a 5 speed manual 'box. The Sierra is smaller and lighter and has a smaller engine, however with its jelly mould styling, it's much more aerodynamical. Luckily, all three of my cars achieve high 30s MPG , although I can drive the Mercedes Benz and the Ford at closer to 70MPH to achieve those figures. 

Have you thought about bending the tubes in half?

[lesapandre]

1 hour ago, LightBulbFun said:

well surely for a suitable comparison then, you should do a run in the MGB at 70Mph cruise instead and see how much of a difference it makes?  

(will be interesting to see what MPG figures I get when I next fill the VDP up as the return trip back home on the M40 on that day was done at a more leisurely 60Mph pace)

I have found the Invacar to be surprisingly economical in that regard, even when relatively flat out on the Motorway, I still achieve a good 45Mpg! (& if we are counting gears like that, the Invacar has an infinite number of gears, until runs out of gears at 45Mph, then it drops into a fixed-ratio-overdrive mode where engine speed will increase with road speed ) 

 

also I wish the VDP was a Hatchback! do you know how much of a Pain in the arse it is trying to fill it up with 8ft fluorescent tubes otherwise?

 

There was a Crayford conversion of the ADO. Wonder if any VDPs were done? VDP might also have done a 1-off.

https://www.aronline.co.uk/the-converters/crayford/bmc-1100-estate/