My car’s repairs are almost done and she’ll be back on the road shortly, so I’ve been thinking some bits over.
I have been exclusively using premium fuels for my 5 - Shell Vpower, BP Ultimate, the various 97 and 98 octanes found around - I use these simply because they improve range, meaning I spend less time at the pumps. Should I really be using these higher-octane fuels, or is this going to cause the car to run too rich? The exhaust gas does have a strong smell, but then again the car has a decat exhaust so the emissions are bound to be less than clean.
Also, I’ve been thinking about those stats about 80% of engine wear/damage happening when running cold - will my 5 respond well to Magnatec oil? Will this help prolong engine life significantly?
I too enjoy the benefits of shell V-power, not sure it increases the range but dees make the car feel a bit more lively due to the engine managment in my Mk2.5 being able adjust spark timing for higher octane fuels etc. Not sure that would happen in a Mk1 though? ? Could be wrong but I don’t think they have knock sensors fitted? Maybe the 1.8’s did ? ? Higher octane fuels shouldn’t make it run richer, they are just less prone to knocking. I presume you have your timing set to 14 degrees btdc?
I was never a big fan of Magnatec stuff as from what I understood its more mineral based rather than synthetic. The MX5 engines like a nice thin oil to start up with and get round quickly. I have always used Mob1 or Millers full synth. When I had my Mk1 1.6 it was surprising how much difference the engine felt when I dumped the slop that the garage had put in and stuck in some decent lube.
Will this help prolong engine life significantly?
Regular oil changes will, I don’t buy all that patter about it sticking to the engine internals. I’d rather the oil get round quickly upon start up and not turn to p*ss when the engine gets hot.
Just my two pence worth but there was a guy on the old MX5 forums call ‘oilman’ - that guy knew his stuff and always went the full synth direction.
Rich
PS. I read somewhere that different oils in high performace engines have been know to make up to 10bhp difference. Not sure it’s true but I suppose it does sound possible. But hey, not everything on the internet is true
I’m with Rich on this. On the high octane fuel thing. I did a load of back to back tests about 6-7 years ago with Ultimate and the standard BP product. Over 5000 miles of alternating tanks full [and I mean full, typically 42 litres] there was no difference in fuel consumption and no discerable difference in performance. I used to get a little HLA rattle at start up, changed from a semi synth to Mobil 1 5/50 and I have found no rattle at all. Higher grade petrol will not make your car richer, it will make you poorer[;)], and the oil companies richer!! Regular oil changes and drive the little car hard, hit the rev limiter every now and then and enjoy all the performance that is available to you…yep that word again ENJOY…
Actually no, I don’t - I have heard of this trick, but always wondered why Mazda wouldn’t have set it as default it if’s so much better? Also, economy is important (I cover 200 miles a week), and this could potentially increase consumption no?
Thanks - that seems to be the consensus on here, so at the next minor service (I have to have it done at Dandy to validate mechanical warranty) I’ll bring along fully-synth instead.
Haha - the old ‘Italian tuneup’ eh! I will try to turn off the neurotic part of my brain that says ‘this is going to break something’ and just enjoy the twin-cam ‘rawwwrrr’ more often! Also, I’ve noticed the strong bias in the torque curve toward the higher rev range.
Interesting - I think I shall try this experiment. Once I get the car back I’ll do a week’s trial of each and see what happens.
Thanks for all the help chaps! Have a good weekend. PistonHeads is ticking along without me today so my weekend has already started… I have done absolutely nothing. At all. Hella yeah.
There is no impact on fuel economy. The reason why Mazda didn’t set it to 14 degrees for the European market is that it would have meant an extra step on the engine production line. One timing setting is used to allow the engine to be used in all markets, including those where there are poorer fuel grades (eg. US regular).
