General gasoline engine owners manual - Cars & Trucks

Try mfg web site or try a google search.

According to page 10-3 of the 2001 Nissan Maxima Owner's Manual:

FUEL RECOMMENDATION
Unleaded premium gasoline with an octane
rating of at least 91 AKI (Anti-Knock Index)
number (Research octane number 96)
If unleaded premium gasoline is not available,
unleaded regular gasoline with an
octane rating of at least 87 AKI (Research
octane number 91) can be used.
However, for maximum vehicle performance,
the use of unleaded premium gasoline
is recommended.

Engine "knock" is not just an unusual sound - but over time can cause real damage to the engine. You *should* use fuels with the recommended octane levels, but if you choose to use fuel with a lower octane level due to reduce fuel costs - do not repeatedly use fuel that causes engine knock. Find the "sweet spot" between the cost of lower octane fuel and an octane level that does not cause knocking. Expect fuel economy and performance to drop with lower octane fuels, too.

Good luck!

Try a dealership or even Ebay.com

http://www.ford.com/owner-services/customer-support/ask-ford-faqs?qtype=uq&inputtext=check+engine+zone

http://www.motorcraftservice.com/pubs/content/~WO3EXD/~MUS~LEN/41/03exdog5e.pdf

I checked the manual for 'CHECK ENGINE ZONE' and could find no reference to this for the 2003 Expedition.

There is a Service Engine Soon light though.

I looked all over the manual and could find no instrument cluster light to that effect.

Can you tell me what page refers to this?

Check the Central Junction Box and this diagrams; also can check this in your 2002-Ford-Excursion owners manual.

Fig. Vehicle Speed Control, Page 01 (2002, System overview, Gasoline engines)




Fig. Vehicle Speed Control, Page 02 (2002, System overview, Diesel only)





Fig. Vehicle Speed Control, Page 03 (2002, Gasoline engines)









Fig. Vehicle Speed Control, Page 04 (2002, Gasoline engines)








Fig. Vehicle Speed Control, Page 05 (2002, Diesel only)





Good luck.

eBay has been my source for years. Dealers are my last resort.

Only short term when absolutely necessary...

Your owner's manual says:
"
Fuel selection:
Select premium unleaded gasoline with an Octane Rating
of 91 (Research Octane Number 96) or higher for optimum
engine performance. However, if such premium type
cannot be obtained, you may temporarily use unleaded
gasoline with an Octane Rating as low as 87 (Research
Octane Number 91)."

The information for this should be in your owners manual. If you don't have an owners manual I would call a dealership and ask them. Different engines require different maintenance. I personally change mine about every 50,000 miles in my gasoline vehicles.

This should be stated in you owner's manual. Most cars are fine on 87 octane. Some high performance engines will give more power with higher octane fuel.