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MichaelH

TR4 MPG

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Hi all 4/4A drivers

Having owned the car since the seventies I have always had poor (approx 20) mpg. In my wisdom I got out my SU carb book and applied the details to my carbs, including going back toTW needles

The result is sweet tick over and seems more mpg, the plugs are pale chocolate.

Tell me what mpg a good standardish 4 will return when driven as road car, ie without competitive driving?

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Just back from 2500 mile round TRip to Italy, including lots of Alpine passes and autostrade/autoroute cruising at 70 (ish).

 

Never missed a beat, and got just over 30 mpg, with a "fastish" road engine, but fully laden.

 

Molto bene!

 

Mike

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1991 cc TR3 FRE engine fitted circa 1968, gave me 41 MPG driving from Leatherhead to Lincoln, & back.

Speeds generally 65 - 70.

 

Around town I get more like 30 MPG. But it does show what's possible.

 

Bob.

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Hmmmmm.... will have to check mpg over several tankfulls and report back

very pleased with 75 miles on the 1st quarter of the gauge so far, but as we all know, the gauge and the tank don't always directly relate

I am sure that better mpg and in my case a quieter exhaust will encourage greater use/acceptabilty of the car : but recent sunshine sure helps!

Michael

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Over 30 mpg on a recent continental trip of 1500 miles, with a good mix of motorway and local driving. It surprised me how good it was.

Dave

==

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On the 2014 Club Triumph Round Britain Reliability Run my 4A returned 34.05 mpg (and this is a true figure corrected for a known odometer over-read of 1.5%). The running average speed over the weekend for the 1,997 miles was 51.28mph. I have HS6s with standard TW needles, K &N air filters and 123 ignition. The original "C" type SAH head has been skimmed a couple of times.

 

Tim

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On the contrary Mike, we shared the driving pretty equally and both drove "progressively" on frequent occasions! I think the optimisation session on the rolling road with Peter Baldwin had a good influence.

 

Tim

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That sounds really encouraging to get north of 30 mpg would be great

My car is similar 123 ign, piper yellow cam, 9.5 ish comp ratio, 87 powermax pistons running on roller rockers but those are just coming off in favour of standard 1:1.5 rockers, SUs TW needles and K&N filters

3.7 diff o/d box

Michael

PS av 51 mph is quick

Edited by MichaelH

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Yes Mike the event is pretty full on but over half the mileage is on motorways or dual carriageways subject to a 70mph limit and most of the rest on single carriageway roads with a limit of 60mph. The 200 miles of A9 from Perth to Latheron is traversed between 3.00am and 7.00am on the Saturday morning and traffic is light. We use great A and B roads around Scotland when for much of the time the only cars you see are other Triumphs on the Run! Much if the Welsh section is done in the early hours of Sunday morning when, with decent headlights, the car can safely be given some beans.

 

It's a really stunning event, you should try it some time. But then again as a twenty-time veteran of the RBRR in my 4A I would say that wouldn't I!

 

Tim

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I usually get around 32MPG on twin 40 Dellortos, long distance motorway driving I normally get around 320+ out of a tank.

Stuart.

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My 4 (standard carbs and ignition, early inlet manifold, 4A head, o/d) returns 27-31 mpg pottering around and mid 30s on runs.

 

Mike

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I would imagine that a car with the rear screen and hard top on will return better mpg than a convertible TR4, as it would be more aero dynmically efficient?

 

Does anybody have any experience of this aspect?

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I have always thought this must be the case but would be very interested to see comparative figures. You would think that the hard top would give somewhat smoother air flow than the surrey but would this offset the greater weight? .

 

Tim

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I have always thought this must be the case but would be very interested to see comparative figures. You would think that the hard top would give somewhat smoother air flow than the surrey but would this offset the greater weight? .

 

Tim

 

I would question whether the hood and frame weigh more than

an aluminium hardtop setup.

 

Plus - the soft trim for a soft top will weigh a bit more than the

hard trim for a surrey top.

 

MikeF's figures tie in the TR 2100 records. Not mine, but those

of the original owner, who kept records from new (April 1962)

until he sold it to me in 1977.

Driving style always will be a major factor - the original owner

was an about-to-retire civil servant who was sympathetic to the

car (removing and cleaning the sump at every oil change and

even rotating the tyres), recording everything in his little book

(passed on to me). This shows every gallon of petrol bought

and the mileage. End figure - 29. something.

 

AlanR

Edited by TR 2100

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Alan, I probably worded my post confusingly. I have a steel hard top and of course it is much heftier than the surrey and frame. What I meant was would the theoretical small potential fuel economy benefit from fitting the smooth hard top compared to the less smooth surrey be cancelled out by the greater weight of the hard top?

 

BTW your civil servant was pernickety. I rotate wheels every 5,000 miles, including the spare, and have always kept a record of fuel added and corresponding mileage to keep track of consumption. I would draw the line at dropping the sump at every oil change however! Whilst 29mpg is in line with contemporary road test results I think it is a bit disappointing as an overall figure, maybe it relates to a preponderance of short journeys. Wherever possible I avoid taking the 4A on a journey too short to fully warm the engine and when I take it out of the garage to wash (rarely) or work on (frequently) I always avoid a cold start and push it to and fro. My drive has a slight slope so pushing it back into the garage reminds me of packing down tight and low in the scrum at school. I am sure the neighbours think me very odd.

 

Tim

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I just have a soft top on this car, so nearest I can get is my former Spitfire 1500. I had a hard top for winter and a soft top for the rest of the year. If there was any difference in consumption it was unnoticeable amongst all the other variables affecting consumption.

 

Mike

www.chrisfennerfund.org

Edited by MikeF

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Ran the car to as empty as I dared - the fuel needle was left of the empty: managed to do 247miles

then filled it up with 45 liters =10 gallons

checked the plugs which were a bit pale so wound the jets down one flat

I drive around keeping up with the traffic and I do 70 on dual carriageways . My speedometer is accurate as I had it adjusted by Speedograph Richfield in Nottingham (good service) Thinks must put my sat nav in and check the speed readings

Michael

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+1 for Speedograph Richfield. They overhauled/adjusted my speedometer over twenty years ago and it is still cock on according to satnav - more accurate in fact than that on my 2007 Volvo V70! Still a nice steady needle too. As mentioned earlier the trip meter only over reads by a very acceptable 1.5%, based on several checks against km posts on long motorway stretches.

 

Tim

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My '4A normally gets around 27/28 mpg in town driving, but into the 30's on a run. Overall mileage to and from home for the recent European meeting in Italy where 70/75 was maintained when possible was 36 mpg. Incidentally I'm on SUs (and they were last tuned about 15 years ago!)

Ian Evans

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Last weekend I completed Club Triumph's 50th anniversary Round Britain Reliability Run in the 4A with hard top fitted. This comprised a little over 2,000 miles of all kinds of road from Motorway to single tracks with passing places in the Highlands. Most of the time we drove up to the NSL where appropriate and the overall true fuel consumption was 35.35mpg at a running average speed of 48.6mph. The worst figure was from the Skiach Services Control, about 18 miles north of Inverness and back to Skiach, 228 miles at 33.96mpg and the best from the Stirling Control to Gledrid services on the A483 just north of Oswestry, 276 miles at 36.59mpg.

 

This is a fair indication of what a TR4/4A in good order should be capable of on a long run if use is made of the good torque (my car will pull uncomplainingly from 20mph in top on a level road) to use the highest practicable gear and unnecessary braking is avoided by use of acceleration sense and judicious smooth throttle adjustments.

 

Tim

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On the same event my TR3 (with a 2138cc engine that has been tweaked) averaged 34.5 mpg over 2223 miles (measured on the calibrated Halda) with the soft top up all the time and the sidescreens on (the drivers side acting as an air brake - half inch gap at the windscreen stanchion!). We too drove to the NSL - honest -_- !

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I note you mentioned the calibrated Halda Ben. I have nothing as sophisticated and no satnav, relying on the car's odometer. However, I calibrated this recently using km posts on a long motorway section and know it reads 1.5% high, I allow for this when calculating consumption figures so as not to kid myself.

 

It was a real pleasure for me and others to meet you and Vicky on the Run and we hope to see you on other future events. See the November Club Torque for the announcement and entry form for next September's Ten Countries Run!

 

Tim

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