Help!! I have a 1999 Discovery that I love more than any vehicle I have ever had. I have always used premium gas in the car; however, I drive about 100 miles per day to work and back. With premium fuel at $2.40 per gallon, it's killing me! Will it hurt my car to run regular unleaded in it, or should I just accept it and keep using premium?

 

Hi Linda,
Not that I'm an expert by any stretch of the imagination,but I remember asking the very same question after buying my Discovery.Your Disco is tuned for premiun fuel,and the pushrod V8 runs at a lower RPM than an overhead cam V8 found in most other SUV's.Because of this your engine is a little more prone to carbon buildup on pistons and valves(not to mention the crud that regular gas leaves in your injectors). Personally I would keep running the good stuff just to keep that engine running clean and smooth.I realise the price of fuel is high,and the Discovery is a thirsty unit,but I tend to look at the long term effects.(I want to keep mine for life). I know this might seem a bit extreem,but have you ever thought of buying a small cheap highway commuter?I do this in the winter months.I'll buy a small used car like a Corolla or a Civic for $700-$1000 and drive it for the winter.I'll then sell it in the spring for what I paid for it(sometimes more).Think of all the fuel and wear&tear your saving on your Discovery.In your case,you could use a small cheap car all week and have a nice cherry running low mileage Land Rover to use enenings and weekends. Again,this is a bit extreem but when I look at my 2001 Discovery II with only 23,000 km's,I't well worth it.
Just my 2 cent's,Ian

 

Newfoundland has good advice.

As somebody who works in the oil industry (and not exclsuively with Chevron), I can tell you that Chevron Premium is the preffered fuel for vehicles such as yours. At the very least, no matter what fuel you use, put an addtivitive in your vehicle every 3-4 fillings. Look at it as a cheap insurance policy.

 

USD $2.40 equates to about GBP ÂŁ1.28, and 1 US Gallon equates to about 0.83 British Gallon, so there's a bit of maths to deal with first.

I don't use Premium Unleaded, and only fill up with Regular Unleaded once every 3 or 4 months, but the price difference here between these fuels is something like ÂŁ0.02 per litre, yes we have our fuel sold to us in litres (4.5459 litres per British Gallon).

In pure cost terms Regular Unleaded is about ÂŁ0.84 per litre here, that works out at USD $5.95 per US Gallon!

This is why I've been running my 1996 Discovery V8i on cheaper Autogas/LPG (Liquid Petroleum Gas), since March 1999 (~53,000 miles), primarily using Unleaded to only start the engine, auto-switching to LPG by ECU, and occasionally using Unleaded as a back up fuel when I run out of LPG.

Running on a Butane/Propane mixture (LPG) is much cleaner to the engine and environment (in terms of harmful pollutants only), and is available here as road fuel, so additives aren't necessary, indeed the engine oil is the same colour when removed from the engine during service as the day it went in. LPG is still a fossil fuel pumping CO2 into the atmosphere, at approximately the same rate as Unleaded.

LPG is less efficient a fuel than Unleaded by some 20%, so you need to take this into account when working out costs.

The raw cost of LPG is around USD $2.82 per US Gallon.

I get mileage of around 12.6 mpg (US) on LPG, which costs USD $0.22 per mile.

Sounds bad, but if you were paying $5.95 per US Gallon for Regular Unleaded, and would likely get mileage of ~15.75 mpg (US), this would be costing you USD ~$0.38 per mile and you'd be as happy as me with the cost of LPG.

We pay an extortionate amount of Road Fuel Tax here in the UK, hence engines and vehicles are usually smaller, more efficient, and produce less pollution per head.

Only the rich (or stupid) exclusively run large engines/vehicles on Unleaded here, most opt for Diesel, but a small minority use LPG or CNG (Compressed Natural Gas - Methane).

In short, you're really lucky to be getting Premium Unleaded so cheap!

 

Very enlightening post Hamrover, Thanks.

 

im paying about $2.60 for regular cheveron.

*shakes fist at oil comanies* bastards!

 

i am running regular, with injector cleaner about every oil change, also use BG products fuel sys cleaner every 5 thousand miles, works for me.

 

I don't believe that running regular fuel is going to damage your vehicle. There are several websites that discuss this, one being www.fueleconomy.gov. From my research, regular gas can cause the engine to knock. Modern engines have knock sensors which will adjust the timing to reduce the knocking. In my experience, this does not cause a reduction in mpgs. My 01 Saab (turbo) is recommended for premium gas. The owners manual states that you can run regular, but you may experience a lag in performance. I still get 32mpg with regular gas, so I am going to stick with that. On the other hand, my 74 Austin Mini must run on premium gas because regular gas makes it run horrible!! Just my 2 cents.