Chimp & 98 Octane
Discussion
Bought a 99S 4.0 Chimp a few weeks ago.
Just been browsing the other boards and noticed someone saying his Chimp misfired with 95 Octance fuel. I've been running mine on 95 Octane because I was told that would be OK, but I've noticed it says uses 98 Octane on the petrol cap - should I be using the more expensive 'super unleaded' (or whatever it's called) which has a 98 Octane rating?
Will using 95 Octane do any damage and will there be a noticeable improvement using 98 Octane?
Also, I wondered about using LRP instead of super unleaded because (I think) it's cheaper - does LRP have a 98 Octane rating and would it be OK to use it?
Thanks.
roadsweeper.
Just been browsing the other boards and noticed someone saying his Chimp misfired with 95 Octance fuel. I've been running mine on 95 Octane because I was told that would be OK, but I've noticed it says uses 98 Octane on the petrol cap - should I be using the more expensive 'super unleaded' (or whatever it's called) which has a 98 Octane rating?
Will using 95 Octane do any damage and will there be a noticeable improvement using 98 Octane?
Also, I wondered about using LRP instead of super unleaded because (I think) it's cheaper - does LRP have a 98 Octane rating and would it be OK to use it?
Thanks.
roadsweeper.
Most Super is 97 in UK and is much better than the standard. If you have a motorway journey using 95 won't hurt and will save you a few quid but performance far better (without a doubt) on Super.
DO NOT USE LRP YOU WILL BREAK VERY EXPENSIVE THINGS!!!
Prepare wallet for surgery, buy Shell Optimax and enjoy.
Adam.
DO NOT USE LRP YOU WILL BREAK VERY EXPENSIVE THINGS!!!
Prepare wallet for surgery, buy Shell Optimax and enjoy.
Adam.
I was told to use regular 95 unleaded by my dealer, I understand all recent cars (mine's 1996) can run on it, weather you need timing adjustment or something is for the techies here.
I did try Optimax for a while, but have to be honest I really didn't notice any difference - apart from a lighter wallet. I'm not doubting some who say it is better they know their cars better than I do, I just couldn't find any difference, perhaps because it's 'only' a 4 litre.
I did try Optimax for a while, but have to be honest I really didn't notice any difference - apart from a lighter wallet. I'm not doubting some who say it is better they know their cars better than I do, I just couldn't find any difference, perhaps because it's 'only' a 4 litre.
Hi manek
I tried your suggestion - the car is on it's way to the dealer for a new engine. I can see how the leaves might improve combustion (assuming they were dry and crinkly) but I think the monkey was a bad idea - do you know how difficult it is to get one of those through the tiny gap for the petrol pump nozzle? Fortunately, I had a sledgehammer and some oil with me so with a bit of thumping, crackling of bones and squelching, it went in fine.
Anyway, for everyone else, don't try that at home.
Regards.
roadsweeper.
I tried your suggestion - the car is on it's way to the dealer for a new engine. I can see how the leaves might improve combustion (assuming they were dry and crinkly) but I think the monkey was a bad idea - do you know how difficult it is to get one of those through the tiny gap for the petrol pump nozzle? Fortunately, I had a sledgehammer and some oil with me so with a bit of thumping, crackling of bones and squelching, it went in fine.
Anyway, for everyone else, don't try that at home.
Regards.
roadsweeper.
For what its worth, I think Shell said Optimax's octane rating was 98.something, i.e. higher than the old super unleaded.
I use Optimax when I can get hold of it, and for what its worth, I think its a bit smoother at lower revs and possibly there is a bit more power. If your car pinks on 95 and doesn't on Optimax, then you've got a clear benefit. If you're after a bit more performance or longer range, then I'd say the benefits are small if they exist at all.
Has anyone measured the performance difference a bit more scientifically?
I use Optimax when I can get hold of it, and for what its worth, I think its a bit smoother at lower revs and possibly there is a bit more power. If your car pinks on 95 and doesn't on Optimax, then you've got a clear benefit. If you're after a bit more performance or longer range, then I'd say the benefits are small if they exist at all.
Has anyone measured the performance difference a bit more scientifically?
My vote goes with Optimax. It's a 98 Octane rating, most Super UL is 97 and regular is 95.
Optimax seems to give my 400 smoother running at low revs, better mpg and it seems to have a slightly lowered the exhuast note, so it sounds better!
I only ever fill up with Optimax, and Super UL in emergencies!
Optimax seems to give my 400 smoother running at low revs, better mpg and it seems to have a slightly lowered the exhuast note, so it sounds better!
I only ever fill up with Optimax, and Super UL in emergencies!
quote:
Hi manek
I tried your suggestion - the car is on it's way to the dealer for a new engine. I can see how the leaves might improve combustion (assuming they were dry and crinkly) but I think the monkey was a bad idea - do you know how difficult it is to get one of those through the tiny gap for the petrol pump nozzle? Fortunately, I had a sledgehammer and some oil with me so with a bit of thumping, crackling of bones and squelching, it went in fine.
Anyway, for everyone else, don't try that at home.
Regards.
roadsweeper.
Interesting comments..
The point is to ensure that the timing is advanced to the correct degree just before pinking occurs
I ve just advanced timing from 26 degree whilst running on standard unleaded back to 32 degrees. The difference in my 1994 500 chim is considerable.
Ie pre advance on rolling road at Well lane West yorks had 300 bhp at fly now feels like 320-340 as it was before running on crap fuel.
Have now permanently moved to Optimax....but where are they selling it....?
Tim
The point is to ensure that the timing is advanced to the correct degree just before pinking occurs
I ve just advanced timing from 26 degree whilst running on standard unleaded back to 32 degrees. The difference in my 1994 500 chim is considerable.
Ie pre advance on rolling road at Well lane West yorks had 300 bhp at fly now feels like 320-340 as it was before running on crap fuel.
Have now permanently moved to Optimax....but where are they selling it....?
Tim
So why are Shell any worse than any other oil company?
I am aware of some research Shell have been doing into, eg, alternative fuel sources such as biodiesel, crop-derived ethanol (fancy putting ethanol in your Chimera? Thought not ...). That doesn't make them saints but I wouldn't have thought they were any worse than any other greedy oil co. And at least they're European.
Or am I missing something?
I am aware of some research Shell have been doing into, eg, alternative fuel sources such as biodiesel, crop-derived ethanol (fancy putting ethanol in your Chimera? Thought not ...). That doesn't make them saints but I wouldn't have thought they were any worse than any other greedy oil co. And at least they're European.
Or am I missing something?
There is an unleaded FAQ on my website which covers this. Some cars will run on 95 U/L, othere need mods such as timing or re-chipping in extreme conditions. Don't use LRP if you have a cat.
Steve
www.tvrbooks.co.uk
Steve
www.tvrbooks.co.uk
My 97R Chimaera 500 seems to be quite happy on 95RON unleaded. I used it for the first couple of tankfuls after I got the car, then switched to Optimax.
To be honest, I didn't notice a lot of difference between 95RON and Optimax, but I've been using Optimax ever since anyway, just to be on the safe side.
To be honest, I didn't notice a lot of difference between 95RON and Optimax, but I've been using Optimax ever since anyway, just to be on the safe side.
On my second tank of Optimax with my 1998 Griff and convinced it is much better than Sainsbury's super.... rather smoother, better pick up and no pinking...and engine note seems different too (but just as good!!!).
Optimax costs are coming down...paid 76.9 last weekend and local garages here in Chelmsford are selling straight unleaded at 73.9.
Worth looking at the Shell website too...it lists Optimax garage locations and you can use their site to print off maps with the details of the garages.
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