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MPG for normal use


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Whilst I know everyone will drive their cars differently and this is not an exact question but how many miles do you get from a full tank of fuel when you use the car as a daily e.g pop to the shops, maybe work etc. I ask the question because since I have owned my TR (during Covid) I haven't been able to attend any club meets nor look at other cars. On a full tank of Tesco momentum petrol (approx £38) I'm getting approx 140 miles. That feels about right by 1965 standards, is this an accurate reflection?

Thanks

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I would say thats a bit low.

You are correct we all drive differently and you'll have a disproportionate amount of choke, with

the driving you describe.

Whenever I check my MPG, and thats not often, on mixed but mostly distance, and not slow, then I seem to always get 30MPG, 

give or take  a decimal point.

John.

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That doesnt seem very much Jase

my tuned TR6 does 200-240 miles on a tank, depending upon ‘enthusiasm’ of the driving :-)

steve

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£38 that’s not to fill it up is it, it costs me more to fill mine it just about empty now and I need to fill up so will check. Mind you I do use supper fuel from shell. And from a early post I don’t do mpg I just put fuel in when it gets to a 1/4 full, may check this time as hopefully got a couple of good runs coming up.

Mike redrose group 

Edited by BRENDA1
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A standard TR4-6 fuel tank is I believe 48 litres or about 10.5 gallons - I wish I could fill that up for £38, especially with a premium fuel - there must be an error there somewhere unless you have a non-standard small tank.

£38 at say £1.30 litre for a premium fuel is about  30 litres or 6.5 gallons, which represents 21.5 mpg, which is still low, but if your driving is particularly spirited, then maybe almost understandable!

Cheers Rich

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21 minutes ago, BRENDA1 said:

£38 that’s not to fill it up is it, it costs me more to fill mine it just about empty now and I need to fill up so will check. Mind you I do use supper fuel from shell. And from a early post I don’t do mpg I just put fuel in when it gets to a 1/4 full, may check this time as hopefully got a couple of good runs coming up.

Mike redrose group 

Do the test for us mike. Whilst not standard it’s close enough as you are still on su’s.

and you are not silly with speed like me. 
 

I rarely fill my tank as I alway seem to have a competition coming up and the most I have in for that is between a 1/4 and 1/3rd.

I add a can full for the last run if it’s close to empty so I don’t get fuel surge away from the pick up point on corners or run out !!!!

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Hi Jase,

the best reading you can do for normal use is a running average.

I normally put in 40 - 44 litres. so according to Richards numbers above I would have had apprx 4 litres in the bottom.

When it is full the gauge reads way over the top. and will take 60 miles to get to the full position.

However it reads'E' empty when I know there is probably still a gallon (5 Litres) in there..

Short runs will kill your MPG. You need to take it on a long long run. Constant speed is best. I do 70ish on the motorways.

With the standard cam I could get 320 from a tank on motorway to the Lakes from West London.  (32mpg)

With my Newman PH1 that dropped to nearer 280ish  (28mpg)

I tend not to go slow so that will also eat the mpg.

Stick to 50 and see what happens.

 

Roger

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On long runs when touring I could usually get a maximum of 360 out of a tankful and thats fairly high speed cruising on twin 40 Dellortos.

Stuart.

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Thanks, £38 is from a 1/4 tank reading. I have stronbergs and it does feel a little low in terms of mpg return. I'm working with extremes and trying to get a feel for it. My Spitfire does about 42mpg, I have a smart Brabus which probably gives me about 50mpg and my 911 smashes all of this with a healthy 18mpg :) having said that it does feel like the TR is using more than the 911 at the moment. Time to renew the rubber diaphragms and check the choke again.

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1 hour ago, Jase said:

Thanks, £38 is from a 1/4 tank reading. I have stronbergs and it does feel a little low in terms of mpg return. I'm working with extremes and trying to get a feel for it. My Spitfire does about 42mpg, I have a smart Brabus which probably gives me about 50mpg and my 911 smashes all of this with a healthy 18mpg :) having said that it does feel like the TR is using more than the 911 at the moment. Time to renew the rubber diaphragms and check the choke again.

Hi Jase,

 what colour are the plugs.  If it is running rich the plugs would be very dark - black.

have you any fuel leaks ?

 

Roger

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48 minutes ago, RogerH said:

Hi Jase,

 what colour are the plugs.  If it is running rich the plugs would be very dark - black.

have you any fuel leaks ?

 

Roger

No, I have no obvious fuel leaks, I'll remove the plugs later and check, will upload some photos. It's running very well at the moment but the choke doesn't need to be out for long when starting from cold, maybe running too rich but I have checked with a colortune.

Thanks

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I always drive about max 200 miles, than fill it up to avoid trouble with my sweetheart.

But about 250-275 miles are possible.

My own measurement is 52 liter for the petrol tank.

I have a wooden lath to check the remaining level if I'm not shure.

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Hi Jase

I would think around the 28 mpg would be normal as already mentioned there's so many different factors these days to say it should be this or that, I don't check my 4a just fill and drive and I would imagine I will be doing that a few times on the return trip to Malvern in August as I'm in tandem with a 6

Chris

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I don't work in 'miles per tankful', not an exact science. Every time I put fuel in the car I note the mileage reading and the quantity of fuel taken. From time to time I fill the tank to the bottom of the filler neck, the difference between two odometer readings at which the tank was completely filled, divided by the total volume of fuel added between them gives a first approximation of the intermediate consumption. To get a true consumption  I reduce this figure by 1.5% since I know my odometer to be over-reading by this amount having checked it against kilometre posts on a long stretch of motorway. 

To return anything under 30mpg I really would have to drive the  car as if I had stolen it. I attach a record of the consumption on all Club Triumph long distance events since 1990.

Tim  

NGP 86D EVENT MPG ANALYSIS 1990 TO DATE.docx

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Our 4A averages around 32-35 mpg. That was sufficient to get us safely between fuel and motel stops across the Nullarbor in 2019 ie about 600km. That is travelling at between 100 and 110kph. With 185/80x15 tyres the odometer is dead accurate but I use the sat nav for mileage readings. It suggests that the odometer would over read by 7% with standard tyres. Interestingly, the car had a milder cam on our first trip to Perth (270 degree duration) and got 38mpg. It now has a 280 degree cam and economy has dropped slightly. Might have to put my right foot on a diet. 

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  • 4 weeks later...

Not a TR4, but a TR3 with an 2187cc engine, 9.5:1 compression, newman PH1 cam, ported, & flowed head.

HS6 carbs RH needles pertronix ign, in re-built dizzy (Martin Jay)with his recommended advance curve.

Just done a 250 mile round trip, part motorway (60 MPH ave) part smaller roads  39.8 MPG total miles so far from engine re-build 823

Bob.

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Thanks Bob, I've adjusted my jets and am now returning almost double what I was seeing previously, couple that with properly inflated tyres and it is even more of a joy to drive.

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  • 2 weeks later...

No matter what I did to my then TR6 I could not achieve any more than 22MPG on a completely rebuilt, rebuild.

Factory brand new figures for PI were 22.5 MPG from new and I am only talking about PI cars so mystified when 30MPG and more claimed.

Now my EFI TR5 is more efficient and so much better fuel consumption but a heavy right foot will bleed that down somewhat.

Regards Harry

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Interesting

my tr6 is bored +60th, is running lucas PI and 123Ignition and gave 148bhp at the wheels at enginuity 

my usual fuel consumption is 25-26 and i once recorded 30mpg on a long motorway run, to the annual TR meet. 

no idea why this is better than original/standard, but i’ve owned the car for 9 years and 25k miles now and the fuel consumption has been consistent

’its a mystery’ as Toyah would say/sing :-)

steve

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Last Monday we drove back from the TR Northumberland weekend in our carburettored TR6 accompanied by friends in a TR4A, a distance of 285 miles according to Google. We both filled up at the garage by the hotel and both cars had about a quarter tank left on the guages when we got home, I have run around a bit since but not filled up yet so I would say 30mpg plus is quite achievable for non PI TRs

George 

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