This is not the only forum I have repeatedly seen mention of Seafoam treatments. I also have a Isuzu Trooper II and read forums relating to that vehicle, where Seafoam is mentioned. Just what is the purpose of doing a Seafoam treatment, and what are the benefits on a high-mileage vehicle?

Also, I see mention here of needing to use Premium fuel in Disco's. Is this really necessary? I mean, these Land Rover (brand) vehicles are used all over the world in 3rd world countries also, where Premium is not available. What happens in those situations?

As an example of fuel use....I have a 1999 Cadillac Deville Concours that I purchased new. Has the 300hp Northstar V8. When fuel started to get near $3.00 gallon, I switched to Mid-grade (89 octaine), and have experienced absolutely NO difference in performance or smoothness of operation. I was under the opinion that fuel injected motors with computer controls (such as the Discovery 1994 I have, or the 1999 Cadillac would adjust the various combustion parameters to compensate for lower octaine fuel to a certain extent. I have certainly found this to be the case with the Cadillac. Has plenty of power, does not run any hotter, etc. I would really like a good explanation or argument for using Premium in a older Discovery.

 

If you dont use premium you will carbon up the engine and that will cause problems. Most engines accross the globe were/are diesel engines so premium is not needed. With premium you will get better mileage and you will have better performance. I will always use premium because I can FEEL a difference between it and regular. I only pay about 5-8 bucks more per fill up so its not that big of a deal anyways if you think about it. As for seafoam, someone will jump in and give you a good explanation of that, I put it in my fuel tank every 3000 miles and it cleans its up very well. It also has other uses, but thats what I use it for the most.

 

SeaFoam is one of a few additives, that if used as an induction cleaner can remove a lot of built up carbon.
As for octane, in Africa, regular octane is 97, similar in Austrialia and New Zealand. They get much better gas formulations then we do.
So yes, 91 plus octane is a must and Seafoam will help your engine alot better.

 

Bottom line, use premium or blow up the engine. Rovers have a high compression engine and high compression engines need higher octane.
All the computer does is adjust the engines timing to compensate for the lack of BTU from a lower octane gas to prevent spark knock. Just because you cant hear it doesnt mean it isint there. It's like the "when a tree falls in the woods and knowbody is around..."
You have a '94, you have a distribitor cap and rotor, your computer will NOT compensate for the cheap gas by adjusting the timing.
If regular is $3.00 per gallon and premium is $3.20 per gallon, which is a common spread (called the ten cent spread) it will cost you $4 more to put in 20 gal of premium BUT you will get better MPG.
For me that is about an extra 50 miles on the same 20 gal of gas. (your MPG may vary)
If you read your owners manual you will see that premium fuel is required. Forget carbon build-up, forget performance, the manufacture REQUIRES premium fuel.
90% of the rest of the world use diesels and where they use gasoline, it is of a higher octane than what we get.
Americans want it cheap and we want it now, so we get cheap gas and cheap cars. If you want a good car then you need to ante up and pay the piper.

 

If you want to run the cheaper gas just take your timing light and retard the timing 3 or 4 degrees, this can be done only on Disco's with a Distribitor.

I had a Isuzu Trooper for years and would bump the distribitor timing up to get more power and I used 93 octane.

You will feel the loss of power as in prime order you have 182 Hp for the 4500lbs that you have to pull around

 

Disco 1's especially carboned up their valve stems and bent valves.
Run good gas in all of them and throw some additive at them for good measure.
Dropping to 87 octane will also cost you about 2 MPG and a loss of low end power.

 

A comment about I should read the owners manual Well in my defense, I didn't get any type of manual at all...so I am sure some of my questions might be answered with an owners manual, but certainly not all. But in any case I don't have a manual or any dealer nearby.

 

Sorry, I assumed that you had a manual. You dont need the dealer to get one. Look on e-bay. If you get a RAVE CD it has the owners manual AND shop manual all on one CD ROM.

 

There is a large sticker inside your fuel door, kind of glares at you whenever you open the door to fill up.

 

Can't use the RAVE CD because I am a macintosh man on a Windoz man.