I have a 1993 prelude with 120k on the clock. I would like give it a basic tune up with an aim to up the MPG very slightly if at all.

I have checked tyre pressures and oil level but before I buy/do anything else I wanted some advice of you guys so I wouldnt waste any time.

My question is what components in an older engine can affect the MPG?

Plugs? Leads? Dissy Cap? Rotor arm? Synthetic or non synthetic oil? Fuel filter? Injector cleanout? Feul pump?

I live in the UK where fuel prices are sky high, 0.92 GBP per litre but we do get 99 octane fuel

Any advice would be great

Thanks

 

I forgot to mention the engine is bone stock! this is my daily driver.

 

Air filter.

Your plugs will make a difference if they are old. As will leads, dizzy...etc. I would start with new air filter and copper plugs. See if it gets you where you want, it's a fairly cheap and easy thing to do.

 

I have a cheap performance air filter would that be ok to use? Or I can buy one from a motor factors thats OEM fitment.

Why copper plugs out of interest?

Will an oil change affect MPG? I would of thought less friction = more freed up power for less/same petrol

As the engine has 120k on the clock can I use synthetic oil or semi synth?

 

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A clean filter is the important thing in my view. If you want to go performance it will probably save a bit. If it's worth the expense I don't know.


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
Why copper plugs out of interest?
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There cheap and I have always liked them. The super expensive kind aren't any better, they just last longer. Your choice really but I thought the whole point of this was to save money

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">
Will an oil change affect MPG? I would of thought less friction = more freed up power for less/same petrol
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I would just do regular oil and filter changes. I doubt the cost of increased frequency of oil changes would gas saved if any.


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As the engine has 120k on the clock can I use synthetic oil or semi synth?
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Not to sure about that one. I think regular is better as it will be less likely to leak out in an old engine. Also it cost a lot less then synthetic. Again, saving you money which is the goal of this exersise but again I am not to sure about this one.


The most important thing to think about is will the cost of whatever you are doing be offset by the cost of the gas you will save. This is why no one buys hybrids yet; you save $400 on gas a year but the car cost $1000s more.


Cheers

 

The most economical route is probably just to follow the manufacturer's service interval recommendations for all these things.

And I agree about the copper plugs too; they conduct at least as well as the platinum/iridium/whatever plugs, and cost a fraction as much. They just don't last as long (I change mine every 20k--$8-10 total), but if you're doing your own labor, that shouldn't be a problem.

 

Using 99 octane is just a waste of money. Run the minimum octane specified by the owners manual. So use 91-92 at most. That will increase your gas mileage. Yes plugs, spark plug wires, cap, rotor, fuel filter, oil, PCV valve will help if they need to be changed. What also helped me was the DIY grounding kit. An air filter with less restriction will help alot too as long as you dont pound on the pedal. Have fun.

 

Just keep your revs under 4k and you're good to go

 

95 octane is our minimum fuel rating here in the UK, but the 99 octane is really the same price depending on where you fill up. Some people say a higher octane can give a more prolonged burn which in turn increases MPG? But im unsure of this.

The aim is to save money as this is my daily driver but if the non copper plugs are only slightly more then it shouldn't make too many odds. Im more interested in gappings of plugs and whether anything can be gained from increasing or decreasing the gap on an older engine, or as stated above I'll just keep with manufacturers specifications.

What is meant by the PCV valve? Ive not heard this mentioned before

I shall double check the grounding cables and may be able to run a couple of extras in as I have access to earthing kits used on telecomm cabinets as part of my job.

The cheap performance air filter I already have so it would cost me no money to install this, I shall make sure it is clean thou. I have a filter cleaning kit and an air compressor with degreasing attachment.

Does anyone know how often the oil should be changed on a h22 prelude?

120k on the clock, I like to think its half way through its life

Thanks for your replies guys