Super

Thunderstorm · Post by **Thunderstorm** » August 14th, 2005, 3:25 pm

That's cool!

When I fill up, I usually have about 10 litres left in the tank, having done 270 to 280 miles. To scared to run out of petrol.
Also never take my car past 4000rpm unless its an emergency.

Not bad mileage for either of us then!

Thunderstorm

valdigre · Post by **valdigre** » August 15th, 2005, 4:38 am

Thunder, you should easily pass 300 miles, cause 1.6 dohc in stock has lower fuel consumption then the V6 by an average of 1 - 1.5 liter.

Take care

valdigre · Post by **valdigre** » August 22nd, 2005, 2:13 am

I think I am going to leave the idea with 98 octane fuel... The price has reached 1.1 Euro

valdigre · Post by **valdigre** » September 6th, 2005, 11:43 am

A small update...After emptying the whole 40 litres of 98 fuel I subjectively find no performance gain and a small (coincidence?) economy boost (about 15-20 kilometers).
Today I refilled with 98 again, we shall see if this was not a coincidence

Famine · Post by **Famine** » September 6th, 2005, 5:23 pm

valdigre wrote:A small update...After emptying the whole 40 litres of 98 fuel I subjectively find no performance gain and a small (coincidence?) economy boost (about 15-20 kilometers).
Today I refilled with 98 again, we shall see if this was not a coincidence

I agree entirely. I've run occasional experiments and I find:

1. No performance gain.
2. Higher flatspot (usually at 3800rpm, slightly over 4000rpm with 97/98/99RON)
3. Marginal economy increase (roughly 0.5mpg, representing a microscopic saving in cost in favour of Super Unleaded).

None of this surprises me. Super Unleaded assists high compression engines by ensuring the fuel detonates in the chambers and not before ("preignition", "knock" or "ping"). The MX-3 V6 has a VERY low compression ratio of 9.2:1 so, while it's capable of advancing the timing to take advantage of the Super Unleaded, it will achieve better performance with 95RON. And, as the engineers always say, you should always run the lowest octane rating you can that gives you no pinging.

Geeman · Post by **Geeman** » September 7th, 2005, 10:45 am

i havent noticed any difference running optimax, or regular unleaded, usually get around 270-280 to a tank

Famine · Post by **Famine** » September 7th, 2005, 2:34 pm

Geeman wrote:i havent noticed any difference running optimax, or regular unleaded, usually get around 270-280 to a tank

I use the "75mph cruise" method.

I frequently run a set journey of 231 miles. There's an uphill (going North) and a downhill (going South). I've collected lots of figures over the past couple of years and, factoring in the time taken, I've come out with a good idea of how much fuel I should use in each direction for a given time. Granted this is subject to several variables, but as a rule of thumb it's not bad.

With Optimax (97RON) it returns about 2 litres less than it ought to for the same journey in the same time with regular (95RON). With BPUltimate (98RON) and Tesco Super Unleaded (99RON - it's really just 95RON with Octane Booster additives) the difference is not as noticeable. BPUltimate is hideously expensive and Tesco Super Unleaded is just crap - you have to add "thinking time" to acceleration, while the engine works out what the hell to do - so I steer clear of both.

Incidentally, the 231 mile trip takes just over a half tank, for ~38mpg.

snellgrove · Post by **snellgrove** » September 28th, 2005, 4:03 pm

valdigre wrote:Hi there,
Your low numbers are scaring me, either you are driving your cars like racing drivers whole the time

yeah, that'd be right

once the engines fully warmed up, its playtime... took mine to the track the other day, started on a full tank .. when it came to fill up, I worked out the miles/ litres-in and was getting 22mpg

hahahaha gotta love what a trackday does to the fuel... oops!

I find that now my engine is all cleaned out from using Optimax, I can use standard 95RON fuel fine.. I think my engine was in crap shape when I bought the car.. previous owner probably never gave it some redlining / proper driving goodness to clear it all out

:edit:

thunderstorm, you posted you never take it above 4000rpm! go on, its fun

what a noise! just make sure the oil is up to temp first....

I drive my car harder these days, ive got a 92 decibel (had it sound tested @ the last trackday) "longlife" (custom made) cat-back system on there... the top-end noise is just amazing, you really get that "6 cylinder scream" coming out of it... plays a note.. it sings... I absolutely love it

petekav · Post by **petekav** » December 8th, 2005, 4:53 am

I run Optimax in Ireland (V-Power) and get 32+ mpg from my V6.
This is nearly always with a 150mile cross-country trip, with at least 75 of that at 60-75mph, and the rest a mix of stuck-in-traffic commuting and zipping down the lanes.

I used to get 38mpg running my old 1.6 Rover on Optimax, so a drop to 32mpg seems acceptable to me for the increase in driving pleasure!

I think if I drove sensibly the whole time and did a long journey at a steady speed I could get a lot closer to 38-40mpg.

Let's face it though, with the gearing and engines our cars have we're never going to get very good mpg.