Fuel Economy?

[Whit]

I posted this in the 7-Series Forum, but I thought I would ask here, as well:
I have a 1988 BMW 750il. What kind of fuel economy should I expect? City? Highway? Mixed? What steps can I take to improve it? I am only getting about 2.5 to 3 km per liter or about 7 mpg max. I know this is a V-12, but another guy I know gets over double this. Anyone?

[uscharalph]

Wow, I don't feel so bad about my 525 any more.

[DanH]

That sounds a little low, but people with V12's are not allowed to complain about fuel economy. ;)

[rickm]

That sounds a little low, but people with V12's are not allowed to complain about fuel economy. ;)

One of the BMWCCA guys here said he gets close to 20 in his 750 when it's on the highway and it taking it easy. 7mpg? Something sounds wrong, not even my nasty old Jeep J20 ate that much gas.

[infinity5]

thats really horrible. if your oxygen sensors are bad, MAF is bad, injectors are bad, fuel fitlers are shot, and your oil is sluge... maybe all of those together :) oh and your transmission is permantly stuck in sport mode ;)

[Whit]

I know it IS bad, huh? 7 mpg seems crazy to me. I have a friend who gets 18 mpg on the highway in his 750. Rather that guess or replace everthing mentioned, how can I diagnose this and repair/replace the correct items? Specifics would be good--even a website or two. Thanks.

[infinity5]

It might have the capability of displaying "stomp Codes" where you mash the pedal quickly while the key is in pos. 2 and the check engine light flashes out codes to tell you whats wrong. i bet the oxygen sensors are bad. they;re expensive, but if they haven't ever been repalced i'd start there. You might also look into the MAFs. they're prohiobitivly expensive new but you might get somenoe to swap out to see if thats the problem. are you loosing power? are you postive both banks are running?

[Qube]

Did you say...

"2.5 to 3 km per liter"

That's INSANE! That's HUMMER slurping down the gas! That would also mean my daily commute would cost me $26 CDN!

Nah, that can't be right.

[CheapCheap1]

Ummm, let's see...
Basically, the following units (you may already have the idea :D) may contribute to your 750 gas guzzling habit:
- Air filter
- MAF
- Fuel filter
- Fuel pump & injectors
- Coils & Spark plugs
- O2 sensor
- DME & Chip

Well, I would suggest you to replace your V12 w/ a V8. So, mathematically, it would save you at least 1/3 of the gas consumption... :)

Otherwise, pls buy a gas station (so you will, at least, get a gas at "wholesale" price to feed your V12 monster)...

[bahnstormer]

7mpg is ferrari lambo territory =] congrats!
i've only achieved it once in my 535 but i had
to try really hard =]