Does Shell Optimax Unleaded work for MB?

[maddog]

Geoff Daniels, Evo's technical guru concluded that if nothing else you should fill up with a premium fuel from time to time to benefit from the cleaning.

I agree failing that a regular dose of fuel system cleaner works wonders

 

[clive williams]

Those old 'uns amongst us will recall the frequency of the de-coke which was an essential part of maintenance on cars up until the late 1970's , the lack of decokes nowadays has more to do with the development of the fuels rather than the engines, most modern mechanics will have never done a decoke.

Nah! Big Prix cars (Formula 1) are supposed to use the most exotic fuels. Shell even state that their optimax was developed in conjunction with Ferrari for Big Prix racing yet the engines are rebuilt (i reckon decoked) after each race.

Clive

500E (Big Prix drivers cars - Michael had one!)
E320CDIT210

 

[maddog]

Nah! Big Prix cars (Formula 1) are supposed to use the most exotic fuels. Shell even state that their optimax was developed in conjunction with Ferrari for Big Prix racing yet the engines are rebuilt (i reckon decoked) after each race.

Clive

500E (Big Prix drivers cars - Michael had one!)
E320CDIT210

The engines are thrown away!! Not sure i'd like to go the same way

 

[SLinKyjoe]

right. £50 worth on 95ron BP in the AMG after 2000miles of Optimax and.................noticiable difference after about 2 miles. car hesitats and didnt want to use full power, but interestingly after a few more miles of hard driving the car adapted and got smoother in its power delievery but i suspect it will be a tad slower! the car is not quite as responsive as it was in S mode, seems the same in anything else and doesnt affect much when tootling about!

am monitoring the fuel consumption so when i have a bit more i will be back on with the findings.

 

[Myros]

SL footnote

308 miles and 63 litres sainbury super and redex, gives about 22mpg. that icludes 180 miles of fast m'way. no real change then, but as it hasn't any adaptive ignition, not surprising really. not bad for a 5 litre though, driven with gusto.

 

[Jay Kilby]

my main car is a Focus RS with lots of mods so she runs 300BHP, now Ford recomends 97+ fuel as the cars technology is primitive and there is no knock sensor, so to stop melting pistons at high revs you run higher octaine fuel.
i suppose the main point here is the fact there is NO KNOCK Sensor which is contrary to some of the earlyer comments about knock sensors.
i cannot tell the differance between BP Ultimate or Shell Optimax and have never used supermarket fuel but i made the decision so long ago i am now not sure why, but the cleaning proertys seem to be familiar.
i have now just purchased a 1981 500 SL which i will collect this weekend the first thing that will go in her is a proper tank of fuel i will report back.

Jayk

 

[philharve]

Hi All

I'm now on my fourth tank of Optimax and my car continues to run sweetly. It is smoother and feels more accelerative but the mpg improvement seems now to have max'd. However, this was always my expectation. I am achieving just under 10% more mpg per tank, not per fill up. This equates to an extra journey to/from work and halfway to my Optimax outlet, equivalent to a liitle over 45 miles.

I am perhaps fortunate that I live in an area of the UK (SW Cornwall) where Optimax is relatively cheap: 91.9p/L. I have seen quoted in this Forum Optimax prices far higher than this. I believe I saw one quote in excess of GBP1.00/L. That's a huge price hike. Can such differentiatials ever be justified?

Is there anywhere in the UK were Optimax prices are lower than in Cornwall where we need our cars because public transport is not great? It would be nice to see a map of the UK giving the average Optimax prices at various locations.

 

[clive williams]

Hi All

I am perhaps fortunate that I live in an area of the UK (SW Cornwall) where Optimax is relatively cheap: 91.9p/L. I have seen quoted in this Forum Optimax prices far higher than this. I believe I saw one quote in excess of GBP1.00/L. That's a huge price hike. Can such differentiatials ever be justified?

Is there anywhere in the UK were Optimax prices are lower than in Cornwall where we need our cars because public transport is not great? It would be nice to see a map of the UK giving the average Optimax prices at various locations.

Phil,

I drive all over the country and Optimax is consistantly 6p dearer than Shell Regular and their regular price is consistant with the local prices. Therefore, if it is a £1.00 per ltr then the % increase over Regular is even less than where you are and makes even more sense with a 10% improvement in mileage.

Clive

500E
E320CDIT210

 

[Myros]

stage whatever

280 city grind miles, 51 litres, no m/way to pump up the figures, = 24.9mpg
costs 17.45 pence per mile. so far most expensive, least mpg, but definitely most whoomph. a few m/way trips would have whipped the mpg up, but i couldn't squeeze any in, found some at 91.9 p/litre though

 

[Myros]

I really must get some kip

wrong figures again. Excuse me and all that.
46.59 litres, which makes it 27.34mpg, and 15.28 pence per mile ( at 91.9)
I think I'll repeat the test and see if I can get some m/way in. Worth it for the oomph as far as I'm concerned, but cost might make me swithch back to Sainsbury's Super when they reinstate the vouchers giving 5p off a litre.

 

[Frank Patten]

I've now run through nearly all of my first tank of Optimax. My '93 W124 230TE runs smoother, has better performance and the gearbox is more lively, probably due to it receiving more power. Its like driving a different car. Its not a huge difference but it is noticeable. I keep the gearbox on Economy because the gearbox changes a lot on Sport and I take the view that it is a 13 year old car so why work it too hard. I always thought that the car was sluggish but took the view that it is an estate not a sports car and I have bought quality, not performance. Now I am using Optimax all that has changed. I shall continue using it!

 

[philharve]

Hi Frank

Have you noticed an improvement in mpg? I began to notice improved mpg after my second tank of Optimax. I'm on my 5th tank and the improvement has max'd. I'm getting close to 10% more mpg. It's not a lot but as Optimax is less than my 10% more expensive that the cheap supermarket fuel I was using, I feel the investment in high grade, branded fuel is worth
it. Smoother running, better acceleration and a cleaner engine are other benefits I've noticed. If I were faced with a bill nearer to GBP1.00 per litre, like some members, I think I would stick with Shell unleaded, or equivalent. The detergent in these fuels gives the engine a tune-up, the higher octane gives more performance.

It's interesting that the results of switching to Optimax can be quite dramatic. I suppose it all depends upon the state of the fuel system + engine prior to the switch. An older engine ought to see a bigger improvement compared with a younger one but maybe the quality of fuel used prior to switching is a more significant factor.

REGARDS Phil

 

[philharve]

Update

Hi All

I'm on another tank of Optimax and the mpg improvements have levelled off at around 8 percent per tank. The lowest cost of Optimax in this part of the UK makes Optimax a genuine alternative and not a luxury fuel. The smoother running and greater power/torque is still there. These 3 factors alone are reason enough for adopting these high performance fuels.

Then there is the detergent effect. From evidence provided by other members, detergent-based fuels used over an extended period keep the engine clean and probably contribute to lower maintenance costs in the long run. Decoking (does anyone do this these days?) will be unecessary. Presummably other engine components will last longer too. Maybe there are 4 factors why you should switch to a high performance fuel, if you can find it at the right price.

REGARDS Phil

 

[SLinKyjoe]

the traction device on mine works better with Opitmax. you get a better or smoother reduction in power when it kicks in and better take up when it finds traction. on the normal unleaded at the mo it knocks off far too much power early and takes afew seconds to get it self sorted.

i assume this is down to the timing system knowing it has lower octane fuel and has to re-calculate.

 

[Myros]

latest round of figures for the C280

on a relentless grind of city and town driving. 332 miles, 57.75 litres, that's 26.124 mpg, at a cost of 16 pence per mile at 92.9 p/litre. car feels very oomphy, difficult to resist the extra urge, probaly show in the consumption.
Face very smiley when driving though. I shall try a tankful or two in the Sl and see what that does for my demanour.

 

[Myros]

latest round of figures for the C280

on a relentless grind of city and town driving. 332 miles, 57.75 litres, that's 26.124 mpg, at a cost of 16 pence per mile at 92.9 p/litre. car feels very oomphy, difficult to resist the extra urge, probably show in the consumption.
Face very smiley when driving though. I shall try a tankful or two in the Sl and see what that does for my demanour.

 

[Ramius]

Its an interesting thread this one and has fired a lot of thoughts off. Driving a 3ltr 24v car that weighs as much as a small planet means MPG isnt the highest!

Combining the fuel costs of a 200 mile a week driving experiance with the potential future costs of maintaining an engine of this size ( 148k miles ) makes you a little more interested.

My Father runs a 2004 Eclass (2.6 V6 I think) and by chance he also mentioned changing from his normal Tesco fuel to Optimax. He has said that he feels the car runs differently, he too is chasing a better MPG.

With the amount of posts appearing here and in other areas relating to this topic, I think a few tanks of the good stuff may be in order to guage this for myself.

Heres to cheaper, leaner and healthier fuel!

 

[clive williams]

Hi All

Maybe there are 4 factors why you should switch to a high performance fuel, if you can find it at the right price.

REGARDS Phil

Phil,
Can I add another to your list? I now fill up with Optimax for two tank loads prior to an MOT and deliver the motor with a tankful. It seems easier to get through emissions these days even though the cats have been abused and are 225k old.

Clive

500E
E320CDIT210

 

[philharve]

I now fill up with Optimax for two tank loads prior to an MOT and deliver the motor with a tankful. It seems easier to get through emissions these days even though the cats have been abused and are 225k old.

Hi Clive

OK, that's a 5th reason to use Optimax.

I wonder if super fuels, like Optimax, rejuvinate cats by cleaning them and help them to work more efficiently? If it does, this helps reduce maintenance costs as well as repeat fees for MOT retests.

REGARDS Phil

 

[mercmonkey]

http://fifthgear.five.tv/jsp/5gmain.jsp?lnk=601&featureid=143

they did a test with a scooby and did notice some results