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TR2/3/3A TR3 Gas Mileage

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spineguru

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I am getting pretty bad gas mileage (I think). For a while I had a leak, so that was part of the problem, but now I think I have everything snugged up, and I am still only getting 15 mpg or so. Most of my driving is neighborhood driving with a lot of revving, shifting, and braking, but I thought this was a 25 mpg to 30 mpg car. Anyone else having this experience? If not, what gives?

Also, FYI, it runs great. Fires right up, doesn't miss or sputter, basically runs great. I drove it 150 miles or so this week and all seems well. It just seems to guzzle fuel.
 
I believe the 25-30 mpg was average driving. I recently read an article in Thoroughbred and Classics that stated we should be getting 35 mpg with normal driving and it will dip below 30 mpg with very hard driving. But that is probably Imperial gallons.
I'm assuming your carbs are dialed in. If it's not sputtering, there must be something wrong.
 
I'll get mid-twenties with the usual mix of city-highway driving, higher when all highway miles. You might check your plugs and see if it appears to be running rich. They can be too rich and still not give much indication (other than sooty plugs & exhaust).
 
On my 4 I'll get about 21 mpg city and 27 mpg freeway (75-80 mph w/overdrive). Suggest checking the state of tune as you're getting fewer mpg than my E-type.
Another thought is that if you're "on" it all the time, well maybe that's as good as you'll get.
Bob
 
With my 6 I've been getting around 20 mpg for city type driving and around 22 to 24 mpg highway. I'm very pleased with these numbers.
 
Bryan, I guess my question is how 'stock' is your engine. When I built mine in the mid 70's, it appeared that every 'improvement' would lose me from 1 to 3 mpg. The big obvious ones were the induction system and cam timing, naturally, but even, counterintuitively, so did lightening the rods,pistons,flywheel,... It became seemingly effortless to rev and consequently second nature to run it up more briskly thru the gears. Don't believe everything in print though, the only TR's I knew to be capable of 35 mpg were the early cars with the small SU's and low port heads. And could you possibly have a 4.1 rear axle. I've been thinking about switching to a lower ratio myself since I don't autocross anymore. Have fun and send some rain up here please.
Tom Lains
TS8651, TS58107
 
Thee are several things that contribute to poor mileage. In town, stop and go (especially if you are heavy footed) is going to effect it drastically, but if that alone isen't it It dosen't hurt to check the basics.
Start with the ignition.
Pull the plugs, check for wear, deposits and gap. If one or two look very different from the others this may indicate a problem. Clean or replace the plugs and set the gap, then reinstall.
Pop the distributor cap, look for deposits building up on the terminals and rotor, check for cracks, replace if necessary. Inspect the points for wear, replace points along with with a new condenser at the same time if needed, set the gap. also gently try to turn the rotor. It should turn a few degrees in one direction and spring back,if not the mechanical advance is frozen and needs to be freed up (the weights under the points plate).Also check the vacuume advance, and make sure the ground wire between the points plate and distributor body is intact
apply a dab of grease to the points cam and a drop of oil to the top of the distributor shaft under the rotor then replace the cap.
It would be a good idea to adjust the valves now
check and adjust the timing
then Finally dial in the carbs.
If all is in order you really should be seeing mid 20s MPG out of a stock TR3
Best of luck Guv'na
 
I drive my TR3 almost every day and put 125-200 miles a week on it. I get about 18mpg most of the time, low 20s on the hiway. I would describe my driving style as brisk but not hard.I'm sure I could benifit from new carb shafts and bushings.
Remember that these cars were built when gas was the least of anyones cares and is still one of the cheapest expenses of ownership.
 
banjo /ubbthreads/images/graemlins/iagree.gif
i'd look at the distributor and carbs. check if vacuum advance works and mechanical advance. check plugs. are your carbs overflowing? check the fuel float needle that it closes. check float level at the same time. put timing light on engine while reving it. if you have one that is adjustable check the curve, connect and disconnect the vacuum advance line (keep the carb side plugged so you don't suck air) and compare and verify vac advance working.
good luck
rob
 
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