Hypermiling a classic mini... help?

[yostumpy]

Also you say you've got 12" wheels fitted. What is the overall dia of the tyre compared to that of the std 10", bearing in mind you've only got 998cc of 'A' series to play with, you may be a tad overgeared.

[minispeed]

165/60/12in wheels have a 19.79 diameter. I'm not sure what the 145 10s have but the MPH diff at 3000rpm is 51 for 12s 50 for 10s so I doubt the highway speed gearing would affect fuel economy that much. The 1755013s that I have give 52mph at 3000rpm with that same final drive and I know that they slow the car down a lot during acceleration, they felt like dead weight on my 998.

I'm going to caution again against all the grill block advice because of the known cooling problems that minis have. Yes this is a great hypermilling mod but the mini cooling system is horrible. For those who don't know it was one of the first successfull transverse engine cars so the engineers just used the same style rad that the old front to back engines had and used a pusher fan instead of a puller. I've read somewhere that the pusher style is much less efficient. Also the engineers found that the proper fan was too loud so they chose to use a multi blade design that was not really up to the job. There is a tropical spec fan (which I have and is much better) that they had to put on to sell the car in warm climates. On a hot day a mini can overheat just idling with the UK spec fan. If you do block it do only the right hand side and also direct the open part towards the radiator

As for the ignition it's really easy to check on the mini, all you need is to remove the front grill then loosen the nut that holds the distributor tight and turn it slowly towards the rotation to advance, away from it to retard. You'll also need someone to watch the tach or a tach you can watch from outside the car. Here's a great article telling you how to do it Mini Spares - Article - Distributor - Initial ignition timing set-up.

[HowGudAmI]

The gearing difference is minute Between 10s and 12s. They are almost the same diameter. I bet 12s are less than 1cm more diameter.

Originally Posted by minispeed

165/60/12in wheels have a 19.79 diameter. I'm not sure what the 145 10s have but the MPH diff at 3000rpm is 51 for 12s 50 for 10s so I doubt the highway speed gearing would affect fuel economy that much. The 1755013s that I have give 52mph at 3000rpm with that same final drive and I know that they slow the car down a lot during acceleration, they felt like dead weight on my 998.

I'm going to caution again against all the grill block advice because of the known cooling problems that minis have. Yes this is a great hypermilling mod but the mini cooling system is horrible. For those who don't know it was one of the first successfull transverse engine cars so the engineers just used the same style rad that the old front to back engines had and used a pusher fan instead of a puller. I've read somewhere that the pusher style is much less efficient. Also the engineers found that the proper fan was too loud so they chose to use a multi blade design that was not really up to the job. There is a tropical spec fan (which I have and is much better) that they had to put on to sell the car in warm climates. On a hot day a mini can overheat just idling with the UK spec fan. If you do block it do only the right hand side and also direct the open part towards the radiator

As for the ignition it's really easy to check on the mini, all you need is to remove the front grill then loosen the nut that holds the distributor tight and turn it slowly towards the rotation to advance, away from it to retard. You'll also need someone to watch the tach or a tach you can watch from outside the car. Here's a great article telling you how to do it Mini Spares - Article - Distributor - Initial ignition timing set-up.

Noted and thanks

[wdb]

A 'sometimes' grill block for the Mini should be a piece of cake, if the newer cars are anything like the old (60's) cars. You can get "grill buttons" which make the removal/installation of the grill a snap. Use the stock grille for times when cooling is key, and a plate of aluminum cut to fit at other times. The grill buttons will make changing grilles a sub-minute task.

CLASSIC MINI STAINLESS QUICK RELEASE GRILL BUTTONS (03/29/2011)

[HowGudAmI]

Originally Posted by wdb

A 'sometimes' grill block for the Mini should be a piece of cake, if the newer cars are anything like the old (60's) cars. You can get "grill buttons" which make the removal/installation of the grill a snap. Use the stock grille for times when cooling is key, and a plate of aluminum cut to fit at other times. The grill buttons will make changing grilles a sub-minute task.

CLASSIC MINI STAINLESS QUICK RELEASE GRILL BUTTONS (03/29/2011)

Thanks. I already have grille buttons on the car - they are pretty handy.

My grille is pretty blocked anyway lol. It has 4 spotlights infront of it and there is an aluminum mesh behind the grill slats to add to the looks

[HowGudAmI]

Got petrol today so lets crunch some numbers.

First finding my MPG to compare to - so i am going to use the 3 runs prior:
1. 27.86 mpg uk - 98 miles
2. 28.23 mpg uk - 99 miles
3. 28.06 mpg uk - 98 miles

Distance: 295 miles
Average MPG: 28.05 (UK) or 23.36 (US) or 10.07 litres per 100km

So now onto my results for my first run with effort put towards efficiency -

Distance: 137 miles (the first 30 - 40 of these miles were my 'regular' driving style)
MPG: 30.07 (UK) or 25.04 (US) or 9.39 litres per 100km

MPG improvement: 7.2% or 2.02 (UK) or 1.68 (US)

Thoughts!

Not too shabby for a first attempt imo - particularly as i was not 'eco' for the whole run (i will be this time). Whilst 1.68 US mpg does not sound that great - 7.2% does in my mind...

Plan:

continue with the driving style
try and fix my lack of vacuum advance + check timing - i think that's causing a big loss!. (probably wont be sorted this run - but for the next one.)

next run target:

10% improvement from 28.05 mpg UK (30.86 mpg UK)

What do you guys think?

EDIT : my 'distances' are very accurate - i have seen most modern cars that display higher speed than actual speed (and therefore higher mileage) - when my car says it is doing 30/40/50 or whatever mph - GPS agrees with it - it can be perhaps 1mph out...

[minispeed]

[QUOTE
EDIT : my 'distances' are very accurate - i have seen most modern cars that display higher speed than actual speed (and therefore higher mileage) - when my car says it is doing 30/40/50 or whatever mph - GPS agrees with it - it can be perhaps 1mph out...[/QUOTE]

Also run the GPS for a while and check the odo. For example my miata is 5% off on the speedo as most miatas are, but the odo is dead on. There is not always a direct relationship between the odo and the speedo.

I think the improvement of 10% can be blown away with EOC and proper timing. However adjusting timing by turning the distributer without the vacum advance hooked up and then hooking it up will show the best gains.

Also one more thing I thought of when I bought my HIF44 carb they were saying that some of the SUs have a contact needle where with every opening and closing the needle rubs against the jet which will eventually enlarge the jet. I did a quick search and didn't find info about that for the HS4 but found that there are two typs of jets, red and waxstat. Red is simpler and for performace and waxstat is more economical as it is temp sensitive and will run more effeciently on a cold motor. You also said it had a stage 1, which usually has a needle to run rich, at under 10GBP a stock needle will probalby pay for itself pretty quickly. The waxstat jet at 24GBP is probalby only worth it if you know it is worn out (enlarged) or if you have a red one on. Since EOC means you won't always get up to temp quickly you could see it pay for it self soon.

Chart, Carburetor Needle - Classic Mini

This lists different needle and spring specs. The spring as well as the oil you use is important. If the oil is too heavy it will slow the closing of the carb when you take your foot off the gas.

And a nifty comparison in graph form Minty SU Needle Compare-o-rama I pulled up ADE AAU AAM AAA and AAV and it clearly shows that ADE and AAV are the leanest of that bunch common to HS4s.

Also if you don't have one at about 10-30GBP you can get ram stacks. This will improve the flow of air into your carb which would mean you would have to use less throttle to get the same acceleration, a faster air flow over the needle and better fuel atomization.

[HowGudAmI]

Interesting stuff thanks!.

I never thought that odo's and speedo's could read differently like that!. Im not sure if mine can still though as the speedo is fed by one cable... will have to check. If read 5% over from the factory and a previous owner slowed it down - its not impossible that they could of slowed the odo down so it reads less miles.... will have to drive it pre measured distances and check!.

EDIT, seen as my post count allows:





(the lights are white... not blue)

[HowGudAmI]

Got petrol today again!!!

Pre efforts MPG (3 tank average): 28.05 (UK) or 23.36 (US) or 10.07 litres per 100km
1st hypermile tank: 30.07 (UK) or 25.04 (US) or 9.39 litres per 100km

So now onto my new results from my 2nd tank (todays):

Distance: 110 miles
MPG: 36.96 (UK) or 30.78 (US) or 7.64 litres per 100km

MPG improvement,
Last Tank:22.9% or 6.89 (UK) or 5.74 (US)
Pre-hypermiling: 31.7% or 8.91 (UK) or 7.42 (US)

Thoughts!

Im very impressed this time! considering i have still not made ANY changes to the car - this is driving style only, good for a 2nd attempt!

Plan:

continue with the driving style
try and fix my lack of vacuum advance + check timing - i think that's causing a big loss!.

(same as last time)

next run target:

Optimistic but i would like to hit 40 uk mpg!.

What do you guys think?

[MetroMPG]

23% improvement through driving technique alone is encouraging. Congrats.

I think you're right to want to get at that timing issue asap.