GT550 article

[BRP Tourer]

I just read an interesting article on the GT550 as an "affordable classic" in the Sept/Oct issue of "Classic Motorcycle" magazine. A rather good read but not much new info I didn't already know from other articles.
One thing I did notice is that they are stating these bikes get around 44 mpg, I have read several period tests that gave similar figures. The best I get is around 30 mpg on a mostly stock 75. I thought I had it running pretty good, maybe I need to do some more tuning?

[Vintageman]

What year was the article testing?

My 1973 got 34 MPG last ride I checked. Far from 44 MPG. My GT380 may get that if I cruise only

If you have the needle clips rich and don't really need it hurts gas milage

[Cliff]

My 1974 GT550L has always given me 100-120 miles between fill up and reserve since new. After 150,000 miles, how many gallons is that??

[Ebayru]

I have been getting 40 to 41 mpg with my 1974 GT550. I admit, however, that I drive it pretty easy. The older I get, he more I appreciate reliability.

[Capttwostroke]

I have a 1977 GT550 as one of my daily riders, and have been riding it consistently for three years. I live in and near hilly terrain and ride it often, and I do not ride conservatively. I am a stickler for observing fuel mileage ( I also drive VW rabbit diesels ), and I get 45 mpg on my GT550, compared to 32 mpg for my 1975 GT750. I do however, use non ethanol gasoline whenever possible. ( It is sold in my area, and I believe you or others may find a list of non ethanol gas stations on gas-pure.org). My bikes have not been modified in any way, and are as stock as possible.

[BRP Tourer]

The article was on a '75, the couple other period tests I've read were about the same year or older and touting the same mileage.
My carbs are set up stock, except for a couple Uni pods I installed in the airbox to replace the disintegrated factory cones. Plugs look a nice healthy tan so I believe the mixture is ok. I may play with timing a bit, try to get the mileage up a little. A lot of areas around here are 100 miles between gas stations, and you can't always count on some of the small town places to be open all of the time. I would like to get a bit better range so I don't have to worry so much about filling the tank when I hit a back road.

[Ebayru]

I imagine elevation has an impact on the mileage, also. I live in western NC. My house is at 2,300 ft above sea level and when I go for rides, the elevation can change from approximately 2,000 to 6,000 ft. The carbs are stock and I'd expect that I'd be running rich, but the plugs look good. I've had it at elevations closer to sea level and it seems to run the same.

[BRP Tourer]

My elevation at home in northern NV is at 4900 ft. I sometimes cruse up to the Tahoe area at near 7000 ft. With the stock settings on my '75 it doesn't seem rich. I haven't tried a plug chop at the higher altitude though. As I understand, most bikes built since the late '60's were jetted somewhat lean for emissions so I figure that the stock jetting would be about right for my altitude.