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The mkiv Supra Owners Club

Poor supra economy/mpg - Advice?


cered

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Car: 370BHP BPU-TT VVTI Tiptronic mkiv with 18" alloys. K&N panel filter in OEM airbox and Walbro fuel pump.

 

Having some moderate concern about my Supra, it gotabout 250miles to a full tank of V-Power after being advised it could manage 320miles. Currently its getting around 50-55miles to £20 of BP Ultimate which works out I think 15mpg?

 

I primarily do dual carriageway/motorways miles at the 50-70mph range. The odd footdown moment or two as-well.

 

My first instinct is to run some injector cleaner though it. I've used Wynn's with good results before, any good ones for Supras? or other suggestions to improve economy?

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With a mixture of driving my UK full bpu TT would do 25 mpg and if taken very sensibly

would nudge 30 mpg.

 

I'd check some silly stuff first like tyre pressures and do all the wheels rotate freely, no

sticking calipers, if that's all good then its time to look under the bonnet

Edited by Dnk (see edit history)
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Car: 370BHP BPU-TT VVTI Tiptronic mkiv with 18" alloys. K&N panel filter in OEM airbox and Walbro fuel pump.

 

Having some moderate concern about my Supra, it gotabout 250miles to a full tank of V-Power after being advised it could manage 320miles. Currently its getting around 50-55miles to £20 of BP Ultimate which works out I think 15mpg?

 

I primarily do dual carriageway/motorways miles at the 50-70mph range. The odd footdown moment or two as-well.

 

My first instinct is to run some injector cleaner though it. I've used Wynn's with good results before, any good ones for Supras? or other suggestions to improve economy?

 

Mine is a VVTi BPU TT and I use it daily.

 

My commute is all town driving with a small bit of dual carriageway and I get about 250-275 out of a tank. When I used the car on weekly 180 mile trips I could range 290-340 to the tank depending how I drove and how often I spun up both Turbos:d

 

Hope this helps. There are not many that worry about fuel consumption with these cars but its always good to monitor so you know if anything is going wrong. I did reach 30 to the gallon on one trip just to see if it could be done but boy it was boring:taped:

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I managed roughly 380 to a tank of fuel, that was from London to Lillie in France and local driving there too over 4 days. Wife & daughter were in the car so was taking it easy with a few short pulls. Mine is a VVTi too with a 6 speed.

 

Unless you are doing only local driving and flooring it a lot of the time you shouldn't be getting 15mpg.

 

I would start with the 02 sensors.

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I managed roughly 380 to a tank of fuel, that was from London to Lillie in France and local driving there too over 4 days. Wife & daughter were in the car so was taking it easy with a few short pulls. Mine is a VVTi too with a 6 speed.

 

Unless you are doing only local driving and flooring it a lot of the time you shouldn't be getting 15mpg.

 

I would start with the 02 sensors.

 

Admitelly mines only an n/a, but I was only getting 275miles per tank. After changing the o2 sensors I'm getting 350

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I had the same with one of my old supras, I changed 02 sensor, plugs and all small things but for me it was the vacuum hoses in the engine bay.

I changed all of them and then had half of the consumption!

 

I got around 120 miles on full tank prior to this....

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My car is very very similar car to yours mate; BPU (full decat with RR)-TT VVTI Tiptronic mkiv with 18" alloys. K&N panel filter in OEM airbox and Walbro fuel pump. When using mine i usually get 500km +/-50 and thats average driving with about 1bar or boost most of the time. Id definitely think there is something up with the car alright, no harm in running an injector cleaner. Id look at the O2 sensor as mentioned above. I replaced mine even though the old one was working fine, still have the old one i think.

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For everyone that gets 350 + miles out of a tank of fuel in a supra I have one thing to say to you all

 

" YOUR DOING IT WRONG , YOUR DRIVING TOO SLOW "

 

Wife & daughter in the car... when I am alone now that's a different story... :D

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Without putting a wide band Lambda sensor on it you won't know if it's too rich anywhere. Big wide tyres do no favours for economy, nor do dragging brakes and funny body kits. It's probably due new oxygen sensors and genuine ones work better than Ebay ones. Driving style will of course affect things. If it's done 100K miles it won't be as economical as a fresh engine. Auto boxes aren't as economical as a well driven manual transmission cars. Blah blah.

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  • 6 months later...

My car is the stock 5 speed NA had it from new, does 20mpg on average, may be 24mpg on long journeys, it has 42,000 miles on clock.

 

My brother has a stock TT auto again bought new, 38,000 miles on clock, he has cruise control, 26 mpg local and 34 mpg on long journeys.

 

We took his car to the sle of Man, the TT races and when he was blowing bikes off, foot on floor most of the week the mpg was a joke, circa 12 mpg ish.

 

Let's face it if you nurse these cars for their age and performance and you can average 20 mpg, then this has to be good, 15 mpg is not right, some thing wrong?

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I used to get between 25 and 30MPG from my old Supra both BPU and single turbo...better than the Skyline 350GT I replaced it with.

There are two things that effect economy other than whats already been mentioned and they are lambda sensors and ECU coolant temp sensor, both will cause a default rich mixture and mess with fuel economy.

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