Miles per tank!

[steve.sammut]

Just went to look at a porsche down in dover today and took the ultima. I have never really tested how much you get to a tank, so I filled up both sides and managed 138 miles on one side. Well I thought that was damm good considering i was doing 80 - 90 most of the way and its a 5.9 block.
My old landrover 3.5 could only manage 260 per tank for the same money!

[peterpsg]

Did you find that the gauage reading dropped faster at the start, then slowed down as the tank gets wider?

[menostig]

Yep, drops like a stone, then slows. I shall get a good opportunity on Wednesday to brim it, do 160 miles, then brim it again. Last time I did this journey it was at night where I kept to 90ish the whole way and recorded 27mpg on the carb fed ZZ4. I need to try this again as frankly it was not believable.

[tuxman]

138 miles on one tank wow thats bad go EFI managed 175 miles on a tank this weekened including a day on DW rolling road !!!simon

[crazy of cookham]

I try very hard to get less than 100 per tank. If not I'm just not driving hard enough!

[stig]

I used to get 170 miles TOTAL range in the GTR :-o

Tests continue in the Can-Am

[crazy of cookham]

More concerned with oil consumption. Heavy right foot tends to bore wash. Its difficult on our roads to maintain hard steady driving for longer than seconds.

[tuxman]

interesting point on oil consumption mine used to use a litre every 400 miles or so but since i went EFI there seems to be a vast improvement on the use of oil ,it has reduced usage by 50% don,t know why anybody any idea ??? simon

[bluesatin]

250-270 from both tanks from mixed driving (motorway and country roads). Bruntingthorpe about 5-7 mpg!

[davefiddes]

With EFI there will be less bore washing from having too rich a mixture. Also wonder if having the right advance at part throttle (compared to an AS mech advance dizzy??) means that the cylinder temps will be higher, and get there quicker during warm up. This should allow the piston rings to do a better job at sealing. Course that could be baloney..

[tuxman]

Dave good point about the bore washing ,engine seems to run cooler all round which is a supprise as it is much leaner at tickover than with the carb ,general opinion with a carb is to ritchen them up to make them run cooler so i was a bit worried that mine would run hotter but so far so good .

[steve_d]

tuxman said:

interesting point on oil consumption mine used to use a litre every 400 miles or so but since i went EFI there seems to be a vast improvement on the use of oil ,it has reduced usage by 50% don,t know why anybody any idea ??? simon

Possibly did not have a good seal on the inlet manifold and pulling oil or oil vapour into the induction.

Steve

[davefiddes]

Think that when you have a computer controlling the spark timing what happens is that although its leaner and thus burns hotter the fuel is buring inside the cylinder. This means that the heat is transferred over a large surface area with a lot of it ending up in the oil. When using a mech. advance dizzy the mixture burns half out of the exhaust port at idle so much more of the heat is tranferred to the water jacket. I've certainly found my idle temps to be a lot lower and the headers cooler. Result!