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Had a nice run to the Triumph Day at Stoneleigh Park, first journey outside of my local area the car has made so was a little apprehensive.

Filled the tank at an Esso garage just a couple of miles from home, noticed the needle was moving somewhat slowly on the fuel gauge so filled up again at the same garage on the way back. Was amazed at the results: total distance 138.4 miles, fuel used 16.67 litres. 37.74 mpg!

Is this a record?

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My 88V8 appears to have done the journey on 6 gallons - 200 miles per TomTom - 33.3mpg??? Very dubious.

 

Maybe Stoneleigh will feature in the next series of the X Files. :blink:

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Without wishing to criticise your math competence, there is something seriously wrong there my friend; :unsure: if correct, it’s not a record but a bloody miracle! :blink:

 

Well, I doubted the figures myself, so used an online converter which turned my 16.67 litres into 3.66688 gallons. Also checked the distance covered by comparing trip counter reading with multimap for the same journey. Multimap says the journey is a couple of miles shorter, giving fuel consumption of 36.5 mpg. I'm still very happy with that.

 

My 88V8 appears to have done the journey on 6 gallons - 200 miles per TomTom - 33.3mpg??? Very dubious.

 

An even more remarkable feat. It goes to show is that older cars can achieve the kind of consumption figures associated with modern vehicles. The majority of my journey was in overdrive 4th gear at a steady 2500rpm. Even with modern cars fuel consumption figures improve significantly on long, steady runs.

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Hi, I don't think that is so unbelievable. I replaced my metering unit last year and this turned my 19 miles to the gallon guzzler into a frugal runner offering an average of 36 miles to the gallon over the 500 miles I covered in France on the way to Angouleme in September. Its also a much smoother runner, I can now use overdrive down to almost 30 MPH before replacing the fuel injection system the engine wasn’t delivering the power to run in overdrive top unless the revs were up to nearly 2,000. So on a steady run I think its possible.

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Quelle horreur, I have never managed to get more than 20 to 21 mpg out of a 5 or 6 PI system.No I am not especially heavy footed. All the literature suggests that this is reasonable and to be expected ie about 20mpg. Is the suggestion that a new metering unit will up the MPG. My car got a new Bosch conversion, and the head albeit leaded has been rebuilt in past 1k miles and oil pressure etc suggest taht its had a botom end revbuild.

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I’ve had my 6 for over 30 years; it’s had several M/U’s, sets of recon injectors, PRV's & pumps, it was serviced every 3k miles when it was my daily driver & I kept meticulous records for over 10 years. The most I ever managed was 25mpg on a 400 mile, middle of the night round trip between Essex & Wales. Good urban mpg is around 22 but could drop as low as 18 & these figures were echoed by 2 other PI owning friends of the time (a 5 & another CP 6); I also had a 1978 3 litre Capri for many years & that gave very similar MPG but wasn’t as fast!

 

It’s simple, if you’re getting more than around 28 MPG from a PI with the correct cam, then the M/U is set far too lean, the motor will never deliver its full power potential; I doubt even a modern 6 cylinder 2 ½ litre petrol Jap car could deliver those sorts of figures.

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Out of interest, how much fuel was in the tank originally as the guage on my seems to use very little in the top half then drops like a stone in the lower half. I also get around the 20mpg mark, however in relation to the above capri, my old TVR S2 used to be able to manage above 30 on a run although I think that was a cologne not an essex V6 if that makes any differance?

Edited by salmon
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I'm inclined to agree with the general opinion. I have owned a succession of TR5s & 6s over the past 25-30 years and during that time have had new metering units etc. Never have I had anything approaching 30 MPG let alone 35. On average even on a long run I'm pleased if I get 25. Something strange indeed !!!!

Overdrive at 30 mph...........be very careful, that is likely to damage your overdrive. It is recommended that overdrive should not be engaged at less than 40mph in fourth gear and 30 mph in third.

 

Rodders.

Edited by modelbuilder
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Out of interest, how much fuel was in the tank originally as the guage on my seems to use very little in the top half then drops like a stone in the lower half. I also get around the 20mpg mark, however in relation to the above capri, my old TVR S2 used to be able to manage above 30 on a run although I think that was a cologne not an essex V6 if that makes any differance?

 

The tank was filled both times until the pump shut off automatically, then topped up again very slowly. When filled to the brim, the fuel gauge needle sits above the 'full' marking. I'd certainly agree that fuel seems to go faster in the lower half of the gauge (if you see what I mean).

 

...I doubt even a modern 6 cylinder 2 ½ litre petrol Jap car could deliver those sorts of figures.

 

Did a bit of research on modern 6 cylinder 2.5l cars' consumption figures. Couldn't find any Jap cars for comparison (shame :lol:) However, the closest comparison I could find was the BMW Z4 2.5i Sport - extra-urban 46.3mpg, combined figure 34.4mpg.

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Did a bit of research on modern 6 cylinder 2.5l cars' consumption figures. Couldn't find any Jap cars for comparison (shame :lol:) However, the closest comparison I could find was the BMW Z4 2.5i Sport - extra-urban 46.3mpg, combined figure 34.4mpg.

Assuming those are BMW's published figures, you would be the eternal optimist to actually believe them! :lol:

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Assuming those are BMW's published figures, you would be the eternal optimist to actually believe them! :lol:

 

Proof of the pudding - Z4 forum fuel consumption thread. Reading these guys' experiences suggest from very low 20s up to 34mpg. And they've only got 6 gear ratios to play with :lol:

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Hi guys,

 

I drive a TR6 (150bhp) and a BMW 330i Sport (2002) and consistently achieve 35mpg in the BMW and 30mpg in the Triumph!

 

It's not about published figures it's about inertia and how you understand it. I travel about 60k pa between the two cars and drive them both hard when circumstances permit! but for the large part I drive at a speed which don't stress either of the engines, I also get 150k miles between brake pad changes!

 

I have colleagues at work who drive 3/520d BMW's/C220 CDI Merc's who only better my fuel consumption by 3-4mpg why?

 

So... (if only to justify my petrolhead tendencies) - keep in the right gear and break only when you have too!

 

D

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