Converting Volvo 850/V70 to LPG is it worthwhile?

I have experience of a '96 V90 3 litre auto which had run on petrol up to

175k, we had it gassed with a SGi system which cost £1600. It was costing £60 to fill the tank with unleaded, and now costs £30 (1.5 tanks) of gas to do the same mileage. It does around 22-25mpg on petrol. (mostly fully loaded and / or towing a trailer)

The car does around 30k a year and is now showing 260k miles! In this case its halved our fuel bills.

It runs really well on gas, though does need a slight gas tune up roughly once a year, and as every LPG owner knows the HT components must be A1 for it to run well. We've had the usual ignition amps blowing, inlet manifold gasket sucking in, airbox exploding, faulty PRND switch, steering rack, trailing arm bushes wearing out etc but its never died altogether- tho is getting abit tired now- some oil use and blue smoke at cold start. To be expected at this mileage though.

Previously we also ran a 93 850 2.0 20 manual to 110k, and now a 97 S70 2.5

1. The S70 is miles better on petrol than the 850. The 2.5 10v is the better engine and it consistently does 31-33mpg which I think is excellant. For the same 140bhp its miles faster and you dont have to row it along- hence the better mpg. This will be staying on petrol- mpg is good and it only does 10-12k a year.

If you want a manual the 10v is quite adequate, if an auto go for the 20.

Unless your're doing more than 15k a yr, personnally I dont see the point in gassing it. Tax on LPG is set to soar in the next 24months, so it may end up costing you more in the end!

Looking at an 850 or 70 series, condition and service history is much more important than mileage and age. The best year for an 850 is 96, and 97-98 for a 70 series. Both should come with aircon and make sure it works- evaporators are a weakness.

Personnally I would avoid any auto over 120k; they tend to die anytime after this due to their being no fluid change interval on the service schedule.

If there is tow bar thats been used, the rear springs and shocks will be knackered- barter accordingly. Any suspension clonks or rattles at the front are either anti roll bar bushes (cheap) or wishbone joints (expensive).

Manual clutches all bite about 2/3 the way up, but if its right at the top of its travel its about worn out and they're expensive to replace as there's alot of dismantling involved- only trust this job to someone who's done it before else you'll end up with problems after. Clutches are good for 120k at least on a non-tow car which has been driven sensibly.

Brake discs last around 50k and the cam belt change is due at 80k. It is worth doing the water pump, tensioner and idler, and aux drive belt at the same time (£150 in parts, £100 in labour) as if either fail you can kiss goodbye to the engine.

Finally the engine should start from cold immediately and near silently- any tappet rattle and oil changes have not been regular enough. The 10v should be strong and torquey from virtually no revs at all but run out of puff at

5000rpm, the 20 will feel flat until about 3000rpm, get stronger past 4000rpm then pull hard to 6000rpm. Any misfiring, hesitancy or smoke and walk away. The coolant should be a nice bright blue colour. These engines are not known for headgasket problems but one thats been cooked previously will never be right again- not only does the head warp but the lower girdle too.

Hope thats a start!

Tim..

Reading everything you have written, I would add the option of the 2.5 diesel if economy is the key. My father has a run-out V-reg example. It's also 140bhp but 50mpg is easily achievable. Probably won't get one for £3-4K though.

Good point about LPG fuel duty - I can't see old Gordon leaving that alone for long once public spending is deep in the red.

I'd also second that. My dad has a '98 V70 2.5 TDI, and tends to drive it very hard. It always seems to return at least 40MPG though, regardless of how it's been driven, or if the air-con's being used constantly.

Ben.